THE GROWTH AND SCOPE OF BIOLOGY 5 



and mosquitoes were held to arise by spontaneous generation out of putre- 

 fying substances, while other insects originated through sexual reproduc- 

 tion. His descriptions of the embryonic development of animals, mostly 

 the chick and certain marine forms, are rather accurate. He devised an 

 ingenious scheme of heredity and regarded temperature as a sex-determin- 

 ing agent. He believed that the future of a man could be read from the 

 lines of his palms and that flat-footed people have treacherous disposi- 

 tions. Indeed, a curious mixture of truth, error, and superstition! 



Aristotle's greatness in biology lay not so much in his discoveries as 

 in the fact that he devised a system of thought that dealt with the entire 

 realm of living things. He has long been credited with insisting upon 

 the inductive method, in accordance with which one first collects facts 

 and then draws conclusions based upon them. Other philosophers had 

 been prone to reach a conclusion first and then to decide what the facts 

 must be to accord with the adopted principle. Aristotle did more than 

 urge the inductive method, he used it — part of the time. In general, his 

 work in natural history followed this method. For his scheme of the 

 universe, however, he had not enough facts at his disposal, and here he 

 drew upon fancy. As a consequence, his concept of the cosmic system 

 had what modern biologists consider a serious fault in that it called for 

 the guidance of nature by an outside intelligence. Democritus had come 

 nearer than he to the modern scientific view in that he postulated a natural 

 necessity which determined the course of events; but Democritus had no 

 inclusive theory relating to living things in particular. 



Pliny. — At the time of Aristotle's death, Greek culture was already 

 declining, so that the accomplishments of this naturalist-philosopher 

 represent the highest attainment of antiquity in most fields of science. 

 His successors and followers include Theophrastus, generally regarded as 

 the founder of botany, and a number of others by none of whom was any 

 notable advance made. Specilized phases of biology fared a little better, 

 particularly anatomical studies at Alexandria. 



Rome did not advance far until a much later time. Her chief biolo- 

 gist of this period was Pliny (a.d. 23-79), who is best known through his 

 "Natural History" of 37 volumes. This work was a curious compilation 

 of all the stories of nature which the author was able to gather. Nothing 

 appears to have been rejected, so that fantastic fables abound, along with 

 reliable accounts of the habits of animals, their utility, the particulars 

 of cattle husbandry, etc. Pliny had recourse to two thousand books 

 in the preparation of his "Natural History," and for fifteen centuries 

 thereafter this work supplanted all of them in the popular mind as the 

 source of information regarding natural objects. The author did not, 

 however, add anything of importance to the store of knowledge by his 

 own observations. 



