198 THE PARASITISM OF 



some cases the inclusions multiply readily within the nucleus, and 

 ultimately free themselves from the nucleus and gain access to the 

 surrounding protoplasm. 



3. — In the Intercellular Spaces. — Bodies of similar character 

 may be observed, in much smaller numbers, lying in the intercell- 

 ular spaces, and more rarely still they may be seen lying two or 

 three together in lines amongst the fibrous tissue at the margin 

 of an alveolus, that is to say, in lymphatic vessels. It is difficult 

 to say whether the latter appearances are accidental, but there 

 seems to be no doubt that the bodies are of the same character as 

 the intercellular and intranuclear forms already noted. They give 

 the reaction which so readily distinguishes the body under con- 

 sideration from the globules of altered chromatin which are so 

 often seen in cancer and in other conditions, and with which, 

 perhaps, they might be confused in unstained preparations. 



4. — Position in the Growth. — The position of these bodies is a 

 fact o-f important significance. They occur with greatest frequency 

 in rapidly growing cancers, and in those cases where there is the 

 least sign of cell degeneration. In the case of cancer of the breast 

 they are found most numerously at the outer margin of the mass of 

 cancer, or in the outlying alveoli, and in recently infected lymph- 

 atic glands. On approaching the centre of a mass of growth, or 

 where degeneration has commenced, they begin to be less readily 

 recognised, whereas the many varieties of so-called ^'' cancer para- 

 sites" to which I have drawn attention become more and more 

 numerous. The disappearance of these characteristic forms must 

 not be taken as necessarily implying destruction, for it must be 

 borne in mind how resistant are the adult coccidia in the case of 

 the rabbit, and how they continue to develop in situations where 

 their destruction by decomposition would seem inevitable. 



It will be gathered from what I have said that I have described 

 these bodies with so much detail for the purpose of concentrating 

 special attention on them, as the only bodies yet found which show 

 any probability of being parasitic. Their occurrence within the 

 cell as a distinctly foreign substance, their appearance so strongly 

 suggestive of an organised structure, the staining reactions which 

 they give so distinct from those presented by the normal contents 

 of cells, their great analogy in this latter respect, and especially in 



