COMPARATIVE HISTOLOGY AND PHYSIOLOGY OF THE SPLEEN. 305 



and a yellow periphery ; in the middle of the cell, oval outlines were visible, apparently 

 those of nuclei, and on its surface were several blunt processes or buds. Most of the 

 other special cells were smaller, about eight times the size of a red blood-corpuscle. 

 In a preparation made with methyl salt solution and osmic acid several special 

 cells were seen ; one was very large, markedly yellow, and covered all over with 

 buds. 



On the warm stage they exhibited amoeboid movement at their periphery in a 

 specialised rim of the protoplasm. In one instance there was seen a bud, containing 

 what seemed like a rounded collection of very coarse granules, an appearance probably 

 due to the nodes of an intranuclear network, which became detached so as to form 

 a small round cell. In one of the large cells vacuoles were observed, and in several, 

 creek-like fissures were seen in their outline. Neither the red blood-corpuscles nor the 

 leucocytes showed any tendency to adhere to the surface of the large cells. There was 

 a very rich felt work of fibrin in the plain preparations. 



Nucleated red cells were not found in the films of blood. 



On the morning of the 9th day the blood contained very many large cells, on a 

 rough estimate about forty or fifty in a preparation. They have a characteristically 

 hyaline and glittering surface, characters more marked than of the somewhat similar 

 surface of the leucocytes, and quite unlike those of the surface of the clumps of blood 

 plates. In one case a pear-shaped bud was connected with a large cell by its long pedicle 

 that was contained in a kind of channel in the protoplasm of the large cell ; the pedicle 

 was seen to give way, and there was left a small round cell, with a coarsely granular 

 centre, lying in a depression on the surface of the large cell. Two similar small cells 

 were seen in one instance to come into apposition with a large cell, but almost 

 immediately thereafter they became again widely separate. The nuclei of the small 

 cells show the remarkable dotted appearance to which reference has been made, and 

 each is surrounded by a narrow rim of hyaline amoeboid protoplasm. There was seen a 

 very strong fibrin network. 



On the afternoon of the same day (9th) the number of large cells in the blood was 

 very much reduced. There were no nucleated red cells found in the blood on this 

 day. 



It is difficult satisfactorily to explain the absence of nucleated red cells from the 

 blood, if it be considered that the small cells, which are budded off on the warm stage 

 from the large cells, are probably erythroblasts. These large cells are in abnormal 

 conditions, and it may be that contact with the glass, together with the heat, may have 

 precipitated the detachment of buds or accelerated a process that normally occurs 

 slowly. 



On the 10th day the dog was killed with chloroform. 



The Spleen measured A\ inches in length and weighed 1 3 grammes ; it w T as of a dark 

 red colour ; it was slightly soft and rather full of blood. A scraping of its surface was 

 examined in methyl salt solution, and, after dilution with hydrocele fluid, preparations 



