4 LECTURES 



familiarly known to us, comparative morphology. He 

 applied those facts to the elucidation of zoological prob- 

 lems, and taught that sound zoological knowledge could 

 be gained only by a close study of nature, and a com- 

 prehension of natural laws. 



When we come to think that this great philosopher of 

 ancient Greece flourished over twenty-two hundred years, 

 ago, it is really remarkable what a mass of facts he 

 brought to light and the extent to which he systematized 

 them. Yet it must be remembered that anatomy, as 

 known to Aristotle, was altogether too crude to be of any 

 service in directions other than I have just pointed out. 

 It was, for instance, too inexact for practical use in med- 

 icine and surgery, as was his physiology too erroneous to 

 be of any value in medical diagnosis. He had no concep- 

 tion whatever of the relations between chemistry and 

 physiology, any more than he saw the bearing of zoology 

 upon the medical art and the science of surgery. 



Between one hundred and fifty and two hundred years 

 after Christ, Galen, the celebrated physician of Perga- 

 mus, had largely revised, and to no small degree extend- 

 ed, what had been done by Aristotle in the medical and 

 biological sciences. About the middle of the fourth cen- 

 tury the work was again recompiled by Oribasius, after 

 whose time the world's history passes into the Dark Ages, 

 a period when ignorance and barbarism ruled and all 

 scientific research was practically abandoned and forgot- 

 ten. 



Zoology and botany were brought down to the com- 

 mencement of that epoch in the works of Pliny, who 

 flourished between three and four centuries after 

 the death of Aristotle. We are all more or less familiar 

 with his thirty-six volumes on natural history, consisting 

 as they do chiefly of a compilation of the labors of others 

 in the same field, who had lived during ages prior to his 

 day. The work of that time-honored naturalist, although 

 very valuable in some respects is, nevertheless, loaded 

 with absurd stories, myths, and impossible miracles. He 

 was entirely without any knowledge of even the very 

 simplest laws of classification, as applied to any branch 

 of learning in general, and to the natural sciences in par- 

 ticular. Still, quoting from so many, many authorities 

 as he did, his descriptions of animals, plants and miner- 

 als long remained standard, and profoundly influenced 

 the popular mind and its ideas about such subjects. So, 

 as a whole, his compilations, no doubt, with all their 



