PROTOZOA IN CARCINOMA. 



197 



lying closely together in a cluster. In a successful preparation 

 each of the small ones may be noticed to contain the usual 

 nuclear substance. 



2. — hi the Cell Nucleus. — Similar structures of smaller size 

 may be observed lying inside the nucleus of the epitheHal cell. 

 In this situation the capsule, which is so very characteristic of the 

 intracellular inclusion, is very slight, and, indeed, appears to be 

 absent in most cases. The nuclear inclusions may be single, or 

 may also occur in small groups. Occasionally the bodies may be 



Fig. 53. — Cells from different cancers of the breast, showing various 

 forms of parasites in the cell protoplasm magnified 1,200. 



seen partly within and partly without the nucleus, as if they were 

 passing out from the nucleus into the cell protoplasm. In this 

 reference I would draw attention to an observation of Dr. Ruffer's* 

 who has been able to show that, in certain cases, the nucleus seems 

 to become filled up with numerous small parasites which escape 

 into the cell protoplasm after having burst through the nucleus. 

 The presence of the intranuclear forms does not seem to be so 

 common as the intracellular variety, and, for some reason, they 

 appear more plentiful in certain cancers than in others. The fea- 

 tures shown by many preparations strongly favour the idea that in 



OL 



Fig. 54. — a, b, c, Cells showing single parasites occurring within the 

 nucleus magnified about 800; d, numerous parasites in the nucleus 

 and in the cell protoplasm magnified about 1,000. 



* Ruffer, British Medical [ournaly vol. ii., 1892, p. 993. 



