AND THE LOWER ANIMALS. 'j.j 



the egg itself was a cell in which the germinal spot was 

 the nucleolus, the germinal vesicle the nucleus, and 

 the vitelline membrane and yolk the cell- wall and its 

 contents. Finally, according to the German anato- 

 mist, the segmentation of the yolk, the raspberry-like 

 appearance which we mentioned in another chapter, 

 was but the production of a new series of cells within 

 what he would term, par excellence, the parent cell. 



Schwann's work was very highly thought of, and 

 was supported, almost on its publication, by several 

 distinguished men of science. That this success was 

 deserved will be apparent to those who, on looking 

 back, can recollect the condition of histology twenty 

 years ago.* This doctrine was a very beautiful and 

 captivating one ; it established a decided fundamental 

 relationship between the two grand sections of the 

 organic world ; it showed that all forms of organized 

 matter, whether plants or animals, started from the same 

 developmental point ; and it simplified several com- 

 plex and laborious researches; finally, it was confirmed 

 in numerous instances, by the results of actual obser- 

 vation, and though, at the outset, a few exceptional 

 cases presented themselves, it was quite fair to 

 imagine that, after a while, even these would be 

 overcome, and the theory would become a certain law. 

 Gradually, however, these exceptions became more 

 numerous, and even his most ardent followers were 

 obliged to reject some of the author's opinions. 

 Nowadays the comparison between the ovum and a 

 single cell would hardly receive much support. More- 



* " Mikroscopische Untersuchungen iiber die Uebereinstim- 

 mung in der Structur und dem Wachsthum der Thiere mid Pflan- 

 zen." Berlin, 1832. 



D 



