PROTOZOA IN CARCINOMA. 201 



ing out these processes. If this is well done, the observer need 

 not seek far for stains if he wishes simply to see the parasite. A 

 perfect differential stain to pick out the bodies alone is still to be 

 found. The nuclear stains, such as methyl green, haematoxylin, 

 are not very suitable for that purpose ; like the coccidia in the 

 rabbit's liver, the parasite seems to prefer general protoplasmic 

 stains, and, acting on this principle, the best results of which I am 

 aware have been obtained by Mr. Plimmer, who has used aniUne 

 blue as the special stain for the organism. 



In all well-prepared specimens there is no difficulty in distin- 

 guishing the parasite from the ordinary forms of cell degeneration. 

 It may be of interest to remark in this connection, that when the 

 coccidia in the rabbit's liver were being first investigated, certain 

 pathologists declared the appearances of this now well-known 

 parasite as being given rise to by alterations in the surrounding 



liver tissue.* 



Conclusion. 



The further questions which arise — namely, can the parasites 

 be observed " undergoing reproduction," and can they be observed 

 developing outside the body ? What influence have they on epi- 

 thelial cell multiplication ? and, finally, have they a causative 

 influence on cancer ? — are now the points to be investigated ; and 

 it must not be considered a reproach if, as yet, no definite answer 

 may be given. It will be remembered that, although the very 

 characteristic Coccidium oviforme was recognised so long ago as the 

 year 1839 by Hake in this country, it is only within the last few 

 months that the description of the processes, apparently completing 

 our knowledge of the anatomical changes in the life history of 

 this organism and accounting for the enormous rapidity of its mul- 

 tiplication within the body of its host, have been made known by 

 Dr. R. Pfeiffer. 



* Lang, Archiv. f. path. Anatom., etc., Bd. 44. 



Celluloid. — A new and rather surprising use, says Aiithony's 

 Bulleti?!^ has been discovered and patented by Mr. C. H. Koyl, of 

 Euston, Pa., for Celluloid. By silvering the back of a sheet of 

 this material, Mr. Koyl has succeeded in producing a looking-glass 

 which is not only of excellent quality, but is much less destructible, 

 and has also the advantage of being bent or formed into any shape. 



