38 THE GENERAL CHARACTERS OF CELLS, BY S. STRICKER. 



happen in such a case that the cells have migrated thither 

 from some other part. It is even conceivable that the colour- 

 less blood corpuscles are destined for the regeneration of all 

 the tissues of the animal body. Nor can any solid objection 

 to this view be raised from the stand-point gained by a know- 

 ledge of the history of development. The blood proceeds, 

 indeed, from a different germinal lamina to the epithelia, 

 for example ; but primarily all cells proceed from the segmen- 

 tation spheres, and these again from the fertilized ovum. 

 Lastly, who can determine what influences must be in opera- 

 tion to cause a segmentation spheroid to become an epithelial 

 cell, and whether similar influences may not also act on young 

 cells in the post-embryonal period ? 



Epithelial cells with two nuclei are often seen, and it is 

 generally taken for granted that the division of the nucleus 

 precedes the fission of the cell ; but who can say that every 

 division of a nucleus is followed by fission of the cell ? It is 

 possible that the division of the nucleus in an epithelial cell 

 may be only an instance of arrest of development occurring in 

 a cell which is no longer capable of undergoing division. 



At the time when this article was published, the doubt cast by 

 Cohnheim upon the fact of the pus corpuscles arising from the cells 

 of connective tissue and of epithelium, had an important influence 

 upon the opinion of histologists in Germany. On this account the 

 results of the investigations of Goodsir, Redfern, Virchow, and his 

 pupils, were believed to be founded upon incorrect investigation. 



My later investigations* have, however, shown that the process of 

 division of pus cells can be directly observed under the microscope, 

 and that the proliferation of the cells of connective tissue by division, 

 and of those of the epithelium by endogenous generation, are facts 

 which cannot be disputed.f 



It has in the meanwhile been ascertained in the case of a 

 very easily observed object the blood-vessels that they are 

 partially able to regenerate themselves that fine processes 

 grow out from the capillaries, which are themselves capable of 

 becoming capillaries. 



* Studien aus dem Institutsfiir experimentelle Pathologie. Wien, 1869. 

 t MS. note added by Prof. Strieker. 



