248 TRANSACTIONS OF THE CANADIAN INSTITUTE. [YoL. IT. 



cal conditions inside the blood vessels may be mentioned. It always 

 appeared to me that my cover preparations were far richer in fusiform 

 cells when the blood was obtained from the firmly pressed or squeezed 

 tail of a specimen of Necturus than when the blood was simply allowed 

 to drop on the cover glass from the tail tip. Of course there may be 

 other circumstances which serve to increase or diminish the number of 

 fusiform cells in the preparations, but it seems reasonable to suppose 

 that the pressure which is employed between two cover glasses to 

 rupture the red cells can be as effectually exercised in the blood vessels of 

 the intact body. There is, however, another factor which may be less 

 extensive in its effects. I refer to the giant cells in the spleen of the 

 same animal. In a portion of the spleen of a freshly killed Necturus 

 teased out, a few giant cells are always observable in wiiich one finds one 

 or more large spherules of haemoglobin-holding substance imbedded in 

 the cytoplasma. These giant cells are amoeboid, and it is, presumably, 

 reasonable to suppose that these masses of haemoglobin have been 

 removed from the discs of red cells by the invaginating power of the 

 amoeboid cells. There is in these same cells no evidence whatever of 

 nuclei, either chromatolysed or intact, which could be considered as 

 derived from the red discs, and the only inference possible is that the 

 nuclei and the remainder of the disc cytoplasma have passed away into 

 the general circulation as fusiform elements. What becomes of them 

 finally after they have passed through the cycle of changes described, 

 whether the leucocytes eat up their disintegrated remains, cannot be 

 determined. I do not know why the nuclei of ruptured red cells do not 

 possess the same amount of peripherally disposed cytoplasma as the 

 fusiform corpuscles do, but it is supposable that either the cytoplasma is 

 deposited from the nucleus or that fully formed fusiform cells are derived 

 from red corpuscles only at a certain time in the life history of the latter, 

 and that the conditions demanded by either of these hypotheses is 

 assisted, in the formation and transformation of the fusiform cells, by the 

 chemical and physiological equilibrium of the blood inside the blood 

 vessels. 



We can explain the fate of the leucocytes. No observation has 

 hitherto been made as to the fate of the red cells. My view, I think, 

 presents the easiest and best solution of the question. With it there is 

 no necessity for considering the fusiform elements as hsematoblasts ; it is 

 consistent, furthermore, with Strieker's observations on the transformation 

 of spindles into globular "white" cells* and it specially explains why 



* Quoted by Lowit, op. cit. 



