MODERNBIOLOGY 303 



he found time for carrying out serious theoretical research in the sphere of 

 anatomy and physiology, and though the results to a large extent exist only 

 in the form of brief accounts published in academical proceedings, neverthe- 

 less he has thereby contributed largely to the development of biology. Of 

 one important work that he started on anatomy he managed to publish 

 only the first part, wherein he lays down the principles on which he con- 

 siders that the study of anatomy should be pursued. 



Vkq d'Axyr's classification of the functions of the organism 

 For this purpose he takes as his starting-point, firstly comparative anatomy, 

 as created by Daubenton, and secondly Haller's physiological theories and 

 experiments. He begins by discussing the ancient division of natural objects 

 into three kingdoms and finds that the essential difference lies between ani- 

 mate beings and inanimate things; plants and animals possess common prop- 

 erties that stones and minerals lack. In connexion therewith he strongly 

 rejects the old comparison — which is sometimes repeated even in modern 

 times — between the growth of the organism and that of the crystal; he 

 points out the mathematically regular shape and homogeneous structure of 

 the crystal as contrasted with the rounded forms and variously constituted 

 systems of organisms, but above all he emphasizes the organisms' definitely 

 characterized functions as a peculiarity of life. These functions he divides 

 into the following categories: (i) digestion, (x) nutrition, (3) circulation, 

 (4) respiration, (5) secretion, (6) ossification, (7) generation, (8) irritability, 

 (9) sensibility. The existence of the various functions, together with their 

 respective organs, is then examined in the different life-forms; regarding di- 

 gestion, it is stated that man, the quadrupeds, whales, birds, and crustaceans 

 possess one or more stomachal cavities clearly distinct from the oesophagus 

 and the intestine; oviparous quadrupeds, snakes, selachians, and osseans have 

 a stomach in the form of a single extension; insects, worms, and zoophytes 

 have only one intestinal tube, and plants no digestive canal — the classifi- 

 cation is noticeable as being more reminiscent of Aristotle than of Linnasus. 

 With regard to generation, a distinction is made between viviparous, ovip- 

 arous, and gemmate reproduction. In regard to irritability, he differentiates 

 between insect larvae, worms, and polypi, which have an entirely contractile 

 or muscular body; vertebrate animals, whose muscles cover the skeleton; 

 insects and crustaceans, in which the skeleton covers the muscles; and plants, 

 which possess no free movements. It would be possible, of course, to adduce 

 weighty detailed objections to this system and its various categories; it 

 gives evidence, however, of a careful study and a penetrating analysis of 

 the phenomena of life. And Vicq d'Azyr undeniably possesses a keen eye 

 for certain manifestations and functions of life — far keener indeed than any 

 of his predecessors and many of his successors. 



In particular he keenly criticizes the current theories of the essence of 



