454 



ANIMAL BIOLOGY 



against spontaneous generation — an erroneous theory that sur- 

 vived until the work of Pasteur (1822-1895) in the nineteenth 

 century. (Figs. 152, 294.) 



Malpighi of Bologna and Grew of London, contemporaries of 

 Hooke, Leeuwenhoek, and Swammerdam, may be considered as 

 the pioneer histologists. Grew (1641-1712) devoted all his atten- 

 tion to plant structure, while Malpighi (1628-1694), in addition 

 to botanical studies which paralleled Grew's, made elaborate inves- 

 tigations on animals. The versatility as well as the genius of 



Fig. 293. — Marcello Malpighi. 



Malpighi is shown by his studies on the anatomy of plants, the 

 function of leaves, the development of the plant embryo, the em- 

 bryology of the chick, the anatomy of the Silkworm, and the struc- 

 ture of glands. Skilled in anatomy but with prime interest in 

 physiology, his lasting contribution lies in his dependence upon the 

 microscope for the solution of problems where structure and func- 

 tion, so to speak, merge. This is well illustrated by his ocular 

 demonstration of the capillary circulation in the lungs, which is 

 not only his greatest discovery but also the first of prime impor- 

 tance ever made with a microscope, since it completed Harvey's 

 work on the circulation of the blood by revealing what his experi- 

 ments predicted. (Fig. 293.) 



