The Legacy of Greece Part 8

[6] The word _Biology_ was introduced by Gottfried Reinhold Trevira.n.u.s (1776-1837) in his _Biologie oder die Philosophie der lebenden Natur_, 6 vols., Gottingen, 1802-22, and was adopted by J.-B. de Lamarck (1744-1829) in his _Hydrogeologie_, Paris, 1802. It is probable that the first English use of the word in its modern sense is by Sir William Lawrence (1783-1867) in his work _On the Physiology, Zoology, and Natural History of Man_, London, 1819; there are earlier English uses of the word, however, contrasted with _biography_.

The Greek people had many roots, racial, cultural, and spiritual, and from them all they inherited various powers and qualities and derived various ideas and traditions. The most suggestive source for our purpose is that of the Minoan race whom they dispossessed and whose lands they occupied. That highly gifted people exhibited in all stages of its development a marvellous power of graphically representing animal forms, of which the famous Cretan friezes, Vaphio cups (Fig. 5), and Mycenean lions provide well-known examples. It is difficult not to believe that the Minoan element, entering into the mosaic of peoples that we call the Greeks, was in part at least responsible for the like graphic power developed in the h.e.l.lenic world, though little contact has yet been demonstrated between Minoan and archaic Greek Art.

For the earliest biological achievements of Greek peoples we have to rely largely on information gleaned from artistic remains. It is true that we have a few fragments of the works of both Ionian and Italo-Sicilian philosophers, and in them we read of theoretical speculation as to the nature of life and of the soul, and we can thus form some idea of the first attempts of such workers as Alcmaeon of Croton (_c._ 500 B. C.) to lay bare the structure of animals by dissection.[7] The pharmacopia also of some of the earliest works of the Hippocratic collection betrays considerable knowledge of both native and foreign plants.[8] Moreover, scattered through the pages of Herodotus and other early writers is a good deal of casual information concerning animals and plants, though such material is second-hand and gives us little information concerning the habit of exact observation that is the necessary basis of science.

[7] The remains of Alcmaeon are given in H. Diel's _Die Fragmente der Vorsokratiker_, Berlin, 1903, p. 103. Alcmaeon is considered in the companion chapter on _Greek Medicine_.

[8] Especially the pe?? ???a??e??? f?s??? {peri gynaikeies physios}, _On the nature of woman_, and the pe?? ???a??e??? {peri gynaikeion}, _On the diseases of women_.

Something more is, however, revealed by early Greek Art. We are in possession of a series of vases of the seventh and sixth centuries before the Christian era showing a closeness of observation of animal forms that tells of a people awake to the study of nature. We have thus portrayed for us a number of animals--plants seldom or never appear--and among the best rendered are wild creatures: we see antelopes quietly feeding or startled at a sound, birds flying or picking worms from the ground, fallow deer forcing their way through thickets, browsing peacefully, or galloping away, boars facing the hounds and dogs chasing hares, wild cattle forming their defensive circle, hawks seizing their prey. Many of these exhibit minutely accurate observation. The very direction of the hairs on the animals' coats has sometimes been closely studied, and often the muscles are well rendered. In some cases even the dent.i.tion has been found accurately portrayed, as in a sixth-century representation on an Ionian vase of a lioness--an animal then very rare on the Eastern Mediterranean littoral, but still known in Babylonia, Syria, and Asia Minor. The details of the work show that the artist must have examined the animal in captivity (Figs. 1 and 2).

[Ill.u.s.tration: FIG. 1. Lioness and young from an Ionian vase of the sixth century B. C. found at Caere in Southern Etruria (Louvre, Salle E, No. 298), from _Le Dessin des Animaux en Grece d'apres les vases peints_, by J. Morin, Paris (Renouard), 1911. The animal is drawing itself up to attack its hunters. The scanty mane, the form of the paws, the udders, and the dent.i.tion are all heavily though accurately represented.]

[Ill.u.s.tration: FIG. 2. A, Jaw bones of lion; B, head of lioness from Caere vase (Fig. 1), after Morin. Note the careful way in which the artist has distinguished the molar from the cutting teeth.]

Animal paintings of this order are found scattered over the Greek world with special centres or schools in such places as Cyprus, Boeotia, or Chalcis. The very name for a painter in Greek, _zoographos_, recalls the attention paid to living forms. By the fifth century, in painting them as in other departments of Art, the supremacy of Attica had a.s.serted itself, and there are many beautiful Attic vase-paintings of animals to place by the side of the magnificent horses' heads of the Parthenon (Fig. 6). In Attica, too, was early developed a characteristic and closely accurate type of representation of marine forms, and this attained a wider vogue in Southern Italy in the fourth century. From the latter period a number of dishes and vases have come down to us bearing a large variety of fish forms, portrayed with an exactness that is interesting in view of the attention to marine creatures in the surviving literature of Aristotelian origin (Fig. 3).

[Ill.u.s.tration: FIG. 3. Paintings of fish on plates. Italo-Greek work of the fourth century B. C. From Morin.

A. Sargus vulgaris.

B. Crenilabrus mediterraneus.

C. Uranoscopus scaber?]

These artistic products are more than a mere reflex of the daily life of the people. The habits and positions of animals are observed by the hunter, as are the forms and colours of fish by the fisherman; but the methods of huntsman and fisher do not account for the accurate portrayal of a lion's dent.i.tion, the correct numbering of a fish's scales or the close study of the lie of the feathers on the head, and the pads on the feet, of a bird of prey (Fig. 4). With observations such as these we are in the presence of something worthy of the name _Biology_. Though but little literature on that topic earlier than the writings of Aristotle has come down to us, yet both the character of his writings and such paintings and pictures as these, suggest the existence of a strong interest and a wide literature, biological in the modern sense, antecedent to the fourth century.

[Ill.u.s.tration: FIG. 4. Head and talons of the Sea-eagle, _Haliaetus albicilla_:

A, From an Ionic vase of the sixth century B. C.

B, Drawn from the object.

From Morin.]

Greek science, however, exhibits throughout its history a peculiar characteristic differentiating it from the modern scientific standpoint.

Most of the work of the Greek scientist was done in relation to man.

Nature interested him mainly in relation to himself. The Greek scientific and philosophic world was an anthropocentric world, and this comes out in the overwhelming ma.s.s of medical as distinct from biological writings that have come down to us. Such, too, is the sentiment expressed by the poets in their descriptions of the animal creation:

Many wonders there be, but naught more wondrous than man:

The light-witted birds of the air, the beasts of the weald and the wood He traps with his woven snare, and the brood of the briny flood.

Master of cunning he: the savage bull, and the hart Who roams the mountain free, are tamed by his infinite art.

And the s.h.a.ggy rough-maned steed is broken to bear the bit.

Sophocles, _Antigone_, verses 342 ff.

(Translation of F. Storr.)

It is thus not surprising that our first systematic treatment of animals is in a practical medical work, the pe?? d?a?t?? {peri diaites}, _On diet_, of the Hippocratic Collection. This very peculiar treatise dates from the later part of the fifth century. It is strongly under the influence of Heracleitus (_c._ 540-475) and contains many points of view which reappear in later philosophy. All animals, according to it, are formed of fire and water, nothing is born and nothing dies, but there is a perpetual and eternal revolution of things, so that change itself is the only reality. Man's nature is but a parallel to that of the universal nature, and the arts of man are but an imitation or reflex of the natural arts or, again, of the bodily functions. The soul, a mixture of water and fire, consumes itself in infancy and old age, and increases during adult life. Here, too, we meet with that singular doctrine, not without bearing on the course of later biological thought, that in the foetus all parts are formed simultaneously. On the proportion of fire and water in the body all depends, s.e.x, temper, temperament, intellect.

Such speculative ideas separate this book from the sober method of the more typical Hippocratic medical works with which indeed it has little in common.

After having discussed these theoretical matters the work turns to its own practical concerns, and in the course of setting out the natures of foods gives in effect a rough cla.s.sification of animals. These are set forth in groups, and from among the larger groups only the reptiles and insects are missing. The list has been described, perhaps hardly with justification, as the _Coan cla.s.sificatory system_. We have here, indeed, no _system_ in the sense in which that word is now applied to the animal kingdom, but we have yet some sort of definite arrangement of animals according to their supposed natures. The pa.s.sage opens with mammals, which are divided into domesticated and wild, the latter being mentioned in order according to size, next follow the land-birds, then the water-fowl, and then the fishes. These fish are divided into (1) the haunters of the sh.o.r.e, (2) the free-swimming forms, (3) the cartilaginous fishes or Selachii, which are not so named but are placed together, (4) the mud-loving forms, and (5) the fresh-water fish.

Finally come invertebrates arranged in some sort of order according to their structure. The characteristic feature of the 'cla.s.sification' is the separation of the fish from the remaining vertebrates and of the invertebrates from both. Of the fifty animals named no less than twenty are fish, about a fifth of the number studied by Aristotle, but we must remember that here only edible species are mentioned. The existence of the work shows at least that in the fifth century there was already a close and accurate study of animal forms, a study that may justly be called scientific. The predominance of fish and their cla.s.sification in greater detail than the other groups is not an unexpected feature. The Mediterranean is especially rich in these forms, the Greeks were a maritime people, and Greek literature is full of imagery drawn from the fisher's craft. From Minoan to Byzantine times the variety, beauty, and colour of fish made a deep impression on Greek minds as reflected in their art.

Much more important, however, for subsequent biological development than such observations on the nature and habits of animals, is the service that the Hippocratic physicians rendered to Anatomy and to Physiology, departments in which the structure of man and of the domesticated animals stands apart from that of the rest of the animal kingdom. It is with the nature and const.i.tution of man that most of the surviving early biological writings are concerned, and in these departments are unmistakable tendencies towards systematic arrangement of the material. Thus we have division and description of the body in sevens from the periphery to the centre and from the vertex to the sole of the foot,[9] or a division into four regions or zones.[10] The teaching concerning the four elements and four humours too became of great importance and some of it was later adopted by Aristotle. We also meet numerous mechanical explanations of bodily structures, comparisons between anatomical conditions encountered in related animals, experiments on living creatures,[11] systematic incubation of hen's eggs for the study of their development, parallels drawn between the development of plants and of human and animal embryos, theories of generation, among which is that which was afterwards called 'pangenesis'--discussion of the survival of the stronger over the weaker--almost our survival of the fittest--and a theory of inheritance of acquired characters.[12] All these things show not only extensive knowledge but also an attempt to apply such knowledge to human needs.

When we consider how even in later centuries biology was linked with medicine, and how powerful and fundamental was the influence of the Hippocratic writings, not only on their immediate successors in antiquity, but also on the Middle Ages and right into the nineteenth century, we shall recognize the significance of these developments.

[9] pe?? ?d?ad?? {peri hebdomadon}. The Greek text is lost. We have, however, an early and barbarous Latin translation, and there has recently been printed an Arabic commentary. G. Bergstra.s.ser, _Pseudogaleni in Hippocratis de septimanis commentarium ab Hunnino Q. F. arabice versum_, Leipzig, 1914.

[10] pe?? ???s?? d {peri nouson d}.

[11] pe?? ?a?d??? {peri kardies}.

[12] Especially in the pe?? ????? {peri gones}.

[Ill.u.s.tration: Fig. 5. MINOAN GOLD CUP. SIXTEENTH CENTURY B. C.]

[Ill.u.s.tration: Fig. 6. HORSE'S HEAD. FROM PARTHENON. 440 B. C.]

Such was the character of biological thought within the fifth century, and a generation inspired by this movement produced some noteworthy works in the period which immediately followed. In the treatise pe??

t??f?? {peri trophes}, _On nourishment_, which may perhaps be dated about 400 B. C., we learn of the pulse for the first time in Greek medical literature, and read of a physiological system which lasted until the time of Harvey, with the arteries arising from the heart and the veins from the liver. Of about the same date is a work pe?? ?a?d???

{peri kardies}, _On the heart_, which describes the ventricles as well as the great vessels and their valves, and compares the heart of animals with that of man.

A little later, perhaps 390 B. C., is the treatise pe?? sa???? {peri sarkon}, _On muscles_, which contains much more than its t.i.tle suggests.

It has the old system of sevens and, inspired perhaps by the philosophy of Heracleitus (_c._ 540-475), describes the heart as sending air, fire, and movement to the different parts of the body through the vessels which are themselves constantly in movement. The infant in its mother's womb is believed to draw in air and fire through its mouth and to eat _in utero_. The action of the air on the blood is compared to its action on fire. In contrast to some of the other Hippocratic treatises the central nervous system is in the background; much attention, however, is given to the special senses. The brain resounds during audition. The olfactory nerves are hollow, lead to the brain, and, convey volatile substances to it which cause it to secrete mucus. The eyes also have been examined, and their coats and humours roughly described; an allusion, the first in literature, is perhaps made to the crystalline lens, and the eyes of animals are compared with those of man. There is evidence not only of dissection but of experiment, and in efforts to compare the resistance of various tissues to such processes as boiling, we may see the small beginning of chemical physiology.

An abler work than any of these, but exhibiting less power of observation is a treatise, pe?? ????? {peri gones}, _On generation_, that may perhaps be dated about 380 B. C.[13] It exhibits a writer of much philosophic power, very anxious for physiological explanations, but hampered by ignorance of physics. He has, in fact, the weaknesses and in a minor degree the strength of his successor Aristotle, of whose great work on generation he gives us a fore-taste. He sets forth in considerable detail a doctrine of pangenesis, not wholly unlike that of Darwin. In order to explain the phenomena of inheritance he supposes that vessels reach the seed, carrying with them samples from all parts of the body. He believes that channels pa.s.s from all the organs to the brain and then to the spinal marrow (or to the marrow direct), thence to the kidneys and on to the genital organs; he believes, too, that he knows the actual location of one such channel, for he observes, wrongly, that incision behind the ears, by interrupting the pa.s.sage, leads to impotence. As an outcome of this theory he is prepared to accept inheritance of acquired characters. The embryo develops and breathes by material transmitted from the mother through the umbilical cord. We encounter here also a very detailed description of a specimen of exfoliated _membrana mucosa uteri_ which our author mistakes for an embryo, but his remarks at least exhibit the most eager curiosity.[14]

[13] The three works pe?? ????? {peri gones}, pe?? f?s??? pa?d???

{peri physios paidiou}, pe?? ???s?? d {peri nouson d}, _On generation_, _on the nature of the embryo_, _on diseases, book IV_, form really one treatise on generation.

[14] pe?? f?s??? pa?d??? {peri physios paidiou}, _On the nature of the embryo_, -- 13. The same experience is described in the pe??

sa???? {peri sarkon}, _On the muscles_.

The author of this work on generation is thus a 'biologist' in the modern sense, and among the pa.s.sages exhibiting him in this light is his comparison of the human embryo with the chick. 'The embryo is in a membrane in the centre of which is the navel through which it draws and gives its breath, and the membranes arise from the umbilical cord....

The structure of the child you will find from first to last as I have already described.... If you wish, try this experiment: take twenty or more eggs and let them be incubated by two or more hens. Then each day from the second to that of hatching remove an egg, break it, and examine it. You will find exactly as I say, for the nature of the bird can be likened to that of man. The membranes [you will see] proceed from the umbilical cord, and all that I have said on the subject of the infant you will find in a bird's egg, and one who has made these observations will be surprised to find an umbilical cord in a bird's egg.'[15]

[15] pe?? f?s??? pa?d??? {peri physios paidiou}, _On the nature of the embryo_, -- 29.

The same interest that he exhibits for the development of man and animals he shows also for plants.

'A seed laid in the ground fills itself with the juices there contained, for the soil contains in itself juices of every nature for the nourishment of plants. Thus filled with juice the seed is distended and swells, and thereby the power (= faculty ? d??a??

{he dynamis}) diffused in the seed is compressed by pneuma and juice, and bursting the seed becomes the first leaves. But a time comes when these leaves can no longer get nourished from the juices in the seed. Then the seed and the leaves erupt below, for urged by the leaves the seed sends down that part of its power which is yet concentrated within it and so the roots are produced as an extension of the leaves. When at last the plant is well rooted below and is drawing its nutriment from the earth, then the whole grain disappears, being absorbed, save for the husk, which is the most solid part; and even that, decomposing in the earth, ultimately becomes invisible. In time some of the leaves put forth branches. The plant being thus produced by humidity from the seed is still soft and moist. Growing actively both above and below, it cannot as yet bear fruit, for it has not the quality of force and reserve (d??a?? ?s???? ?a? p?a?a {dynamis ischyre kai piara}) from which a seed can be precipitated. But when, with time, the plant becomes firmer and better rooted, it develops veins as pa.s.sages both upwards and downwards, and it draws from the soil not only water but more abundantly also substances that are denser and fatter. Warmed, too, by the sun, these act as a ferment to the extremities and give rise to fruit after its kind. The fruit thus develops much from little, for every plant draws from the earth a power more abundant than that with which it started, and the fermentation takes place not at one place but at many.'[16]

[16] pe?? f?s??? pa?d??? {peri physios paidiou}, _On the nature of the embryo_, -- 22.

Nor does our author hesitate to draw an a.n.a.logy between the plant and the mammalian embryo. 'In the same way the infant lives within its mother's womb and in a state corresponding to the health of the mother ... and you will find a complete similitude between the products of the soil and the products of the womb.'