130 



PROTOZOA AND DISEASE 



like the one shown below in Fig. 53 ; 12, which resembles the 

 plasmodial form of Scheviakovella, 1 but without the contractile 

 vacuoles of the latter. 



Apart from these forms, there are numerous mitoses, such as 

 those in Fig. 51 at 7 and to the right of 2 and elsewhere, which 

 are tissue-cell mitoses. With these are other bodies, such as the 



FIG. 51. INFECTIVE TUMOUR OF DOGS: THE MIDDLE STAGE. (From a section 

 made by the late Dr. Washbourn. Camera drawing; x 800 diameters.) 



The medium stage of development of a lesion in infective sarcoma of dogs : I and 

 2, tissue mitoses ; 3, amoeboid body escaped from nucleus. The general 

 appearance is characteristic of sarcoma. 



one below 3, which has apparently escaped from the ruptured 

 nucleus above it, and which is probably an early stage of the 

 protozoon-like bodies just referred to. Another striking feature is 



1 One of the Haplosporidia (Caullery and Mesnil). 



