214 SCIENCE IN GRECO-ROMAN ANTIQUITY 



several places at the same time " (De gener. anim., 

 750-3). 1 Aristotle also affirmed the subordination and 

 the hierarchy of beings in the animal scale. The organic 

 individuality becomes stronger as we pass from inferior 

 to superior beings. Only, to Aristotle, this hierarchy 

 was not the result of a progressive and continuous 

 evolution, as Lamarck and Darwin were to maintain. 

 It remains the same for all time, since different species, 

 even those most akin, cannot form a fertile and lasting 

 union. 



Connected with the anatomical generalizations there 

 are physiological generalizations of which Alcmaeon, 

 Empedocles, and the followers of Hippocrates had al- 

 ready set the example. In this domain, Aristotle very 

 clearly established the modern distinction between 

 organs and tissues. Starting from this point, he dis- 

 covered remarkable analogies of the tissues, between 

 hairs, feathers and the prickles of the hedgehog ; and 

 of the organs, between the arms of a man and the wings 

 of a bird, and between the hands of a man and the claws 

 of a lobster or the trunk of an elephant. 



Regarding the assimilation of nourishment by the 

 body, Aristotle held the opinion that foods are cooked 

 by the stomach and are transformed into phlegm or 

 blood according to their degree of cooking. 



Finally, Aristotle opened up several new and fruitful 

 paths in embryology, and his observations on terato- 

 logical cases have not lost their interest. The disciples 

 and successors of Aristotle, although they extended the 

 field of the discoveries made by their master, added 

 nothing to the principles and methods by which he was 

 guided. However, in the vegetable kingdom Theo- 

 phrastus distinguished the cotyledons (the food leaves 

 contained in the seed) from the ordinary leaves pro- 

 duced on the stem ; and recognized the difference of 

 internal structure between palms and other trees. 

 1 Quoted from 14 Gomperz, Penseurs, III, p. 168. 



