246 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VOL. II, 



the two in the latter respect is caused, I maintain, by the nucleus of the 

 fusiform cell enlarging in its transverse diameter and di ninishing 

 consequently in its longitudinal diameter. If one keeps a specimen 

 of blood under observation for a while, during which it is protected 

 from evaporation, one finds that the nuclei of the fusiform elements 

 actually undergo this enlargement in its transverse diameter, the trans- 

 versely placed trabeculae of its network elongate till the chromatin 

 appears arranged in a number of parallel bars transversely placed. One 

 can, moreover, by sudden pressure on the cover glass, rupture a number 

 of red cells, set free their nuclei which undergo the same series of 

 changes that the nuclei of the fusiform cells do, and shortly after the 

 rupture the nuclei of the red cells measured exactly the same (i6/ax 13/A 

 and 14/i). In the free nuclei there is the same transverse enlargement, 

 the chromatolysis and nuclear disintegration. 



2. When a number of nuclei of red cells are set free by pressure there 

 is the same tendency to adhere to each other that is so marked in the 

 case of the fusiform element. To each of these free nuclei there is 

 enough of cytoplasma adherent to constitute the cement necessary to 

 agglutinate them together, and in the masses so formed there is nothing 

 to distinguish them from the thrombi formed of fusiform cells. I have 

 not yet succeeded in observing in them any pseudopodial movement, but 

 it is not often that this is observed in the fusiform elements and it is 

 possible that it is the result of a survival from a well nourished condition 

 in the blood vessels, a condition not at all present under the cover glass. 



3. The free nuclei and those of the fusiform elements have the same 

 staining reactions. In a cover glass preparation fixed with corrosive 

 sublimate or picric acid, in which free nuclei are abundant, the latter, as 

 well as those of the fusiform cells, give with the Indigo-carmine Fluid a 

 blue-black, sometimes an intense black, and with haematoxylin a black 

 reaction. In fact there is the same, or nearly the same stain with all the 

 dyes. There is one important difference so far as the cytoplasma of 

 both is concerned : eosin takes intensely the cytoplasma of the fusiform 

 cells while it stains lightly or not at all the slender protoplasm around 

 the free nuclei. The explanation of this is that the interfilar chromatin 

 (the haematogen) of the nucleus of the ruptured red cell gradually diffuses 

 out from the nucleus into the cytoplasma without being converted into 

 haemoglobin, as it is in the normal corpuscle and that it is this altered 

 chromatin which takes eosin deeply. In some of the fusiform cells there 

 is the same differentiation of the nuclear substance into network and 

 interfilar chromatin, the latter staining deeply with eosin, the former with 

 haematoxylin. There can be no doubt about the fact that in such cells 



