XI PHENOMENA OF ORGANIC NATURE 381 



believed in it ; among others our own great Harvey, 

 the discoverer of the circulation of the blood. 

 You will constantly find his name quoted, how- 

 ever, as an opponent of the doctrine of spontaneous 

 generation ; but the fact is, and you will see it if 

 you will take the trouble to look into his works, 

 Harvey believed it as profoundly as any man of 

 his time ; but he happened to enunciate a very 

 curious proposition that every living thing came 

 from an egg ; he did not mean to use the word in 

 the sense in which we now employ it, he only 

 meant to say that every living thing originated in 

 a little rounded particle of organised substance ; 

 and it is from this circumstance, probably, that 

 the notion of Harvey having opposed the doctrine 

 originated. Then came Redi, and he proceeded 

 to upset the doctrine in a very simple manner. 

 He merely covered the piece of meat with some 

 very fine gauze, and then he exposed it to the 

 same conditions. The result of this was that no 

 grubs or insects were produced ; he proved that 

 the grubs originated from the insects who came 

 and deposited their eggs in the meat, and that 

 they were hatched by the heat of the sun. By 

 this kind of inquiry he thoroughly upset the 

 doctrine of spontaneous generation, for his time 

 at least. 



Then came the discovery and application of the 

 microscope to scientific inquiries, which showed to 

 naturalists that besides the organisms which they 



