1905.] On the Cytology of Malignant Growths. 



349 



Now, the " Plimmer's bodies" are well known in the cells of many 

 cancerous growths (fig. 17), and they are most commonly met with in the 

 young growing portions of the tumour. They appear in the form of vesicles, 

 and consist eventually of a fairly well-defined wall, enclosing a clear space, in 

 which is suspended a small and densely refracting granule. They appear to 

 occur with greater frequency in cancers of a glandular or glandular-epithelial 

 origin.* 



They lie in the cytoplasm of the cancer cells, usually in close proximity to 

 the nucleus. They vary in size from excessively minute bodies to forms as 

 large as the nucleus itself. The special interest attaching to the Plimmer's 

 bodies depends on the fact that they have commonly been regarded as 

 peculiar to cancer cells, although Hondaf believes that he has occasionally 

 encountered them in inflammatory tissue. They have, in fact, been variously 

 interpreted. Some investigators have regarded them as parasitic organisms, 

 more or less intimately connected with the aetiology of the disease, whilst 

 others have seen in them a differentiation of the cancerous cell itself. 

 BorrelJ suggested that they might represent hypertrophied centrosomes, but 

 the observations of Benda,§ who showed that centrosomes and Plimmer's 

 bodies coexisted in the same cell, have rightly been held to disprove the view 

 advanced by Borrel. 



When the foregoing facts are all taken into consideration, the case 

 originally upheld by ourselves || appears to be a strong one. We see no 

 escape from the position that the Plimmer's bodies of cancer represent the 

 archoplasmic vesicles that occur in the normal reproductive cells at the 

 stages already indicated. And this forms an important link in the chain 

 of similarities connecting cancerous tissue with the normal reproductive 

 elements. But in this relation it is of interest to note that we have recently 

 observed bodies, which appear to be closely similar to archoplasmic vesicles, 

 to occur at apparently definite stages in the life history of certain leucocytes 

 which are present in bone marrow. 



General Conclusions. 



To sum up the observations already recorded in this paper, it may be 

 seen : — 



* Greenougb, 'Third Eeport of the Caroline Brewer Croft Cancer Com.,' Harv. Med. 

 School, 1905. 



t Honda, ' Virch. Arch.,' vol. 174. 



% Borrel, 'Ann. Inst. Past.,' vol. 15. 



§ Benda, ' Verh. deutsch. Gesellsch. f. Chir.,' 1902. 



|| 'Boy. Soc. Proc.,' vol. 76 B, pp. 230 et seq. 



