Nucleus of the Animal and Vegetable " Cell'' 225 



the blood to reappear in the epithelium cells. And I am inca- 

 pable of understanding the presence in large quantity, in the 

 Fallopian tube, of red blood-discs and cells such as those at Q 

 in the figure, without supposing that they have here, as well 

 as elsewhere, their origin in parent-cells, such as the epithe- 

 lium cells at n seem to have been. Now, out of blood-red 

 discs (fig. 54, ^), as I long since shewed, are formed cells 

 with processes or arms (/), and out of these is formed the 

 chorion (x) ; which, by the remarks now made, I am endea- 

 vouring to connect with the blood-corpuscles in the circula- 

 tion, — for, it will be recollected, the epithelium cells derive 

 their origin from capillaries such as those in fig. 48, /3, con- 

 taining only blood-corpuscles, and no liquor sanguinis at all. 



And if it be thus possible to trace the elements of the 

 chorion from a free surface, through epithelium cells, to the 

 blood-corpuscles, how much more is it not possible to refer 

 to those corpuscles the elements of the tissues, as well as all 

 nutrition ; seeing that here we have a more direct communi- 

 cation, and no epithelium cells \ 



Having, six years since, investigated the mode of origin of 

 nearly every tissue of the body, and written a long memoir 

 for the sole purpose of communicating the results of those 

 investigations,* I need not here refer to the subject in any 

 other, than a very general manner. In that memoir I stated 

 the tissues to be formed of " corpuscles, having the same ap- 

 pearance as corpuscles of the blood," and did not hesitate to 

 add my belief that the corpuscles having that appearance, and 

 entering into the formation of the tissues, were derived from 

 blood-corpuscles which had been in the circulation. My 

 views are stated somewhat in detail, in the description of figs. 

 47 and 48 of Plate II. ; to which description I refer, and would 

 here simply add, that there was no liquor sanguinis in the 

 capillaries represented in those figures ; that I believe it to 

 be the hyaline from the centres of blood-corpuscles that 

 escapes from the capillaries for nutrition and the formation 

 of new parts, — globules of which hyaline become red cyto- 

 blasts, exactly like those still in the circulation ; and that, 



♦ " On the Corpuscles of the Blood," I'art 111., Phil. Trans. 1841. 



