THE PARASITIC PROTOZOA OF THE RED C4R0USE 329 



chiefly composed of ectoplasm. Very few pseudopodia were sent out at any one 

 time. There is a nearly central nucleus, often possessing a karyosome. Food 

 vacuoles containing partially digested food particles and bacteria were seen (Fig. 61). 

 The granular endoplasm may contain a vacuole (Figs. 58, 59). 



Amoeboid organisms, from the irregularity of their shape, are not easy to 

 measure precisely. More or less rounded forms may measure 60 fj. in diameter (Fig. 

 61) with a nucleus 10^ in diameter. Other specimens of the parasite (Figs. 59, 60, 

 63) measure from 20^ to 40^ across, with a nucleus of 5^ to 8^ in diameter. 



In preparations stained with Delafield's haematoxylin the nucleus was seen to be 

 spherical (Figs. 58-61) with a nuclear membrane on which the chromatin could some- 

 times be clearly seen in the form of granules (Fig. 58). The whole nucleus, 

 however, is somewhat poor in chromatin, though a karyosome may be present 

 (Figs. 58, 60, 63) as before mentioned. 



Division by binar}' fission was seen once in life, the process taking about thirty 

 minutes for completion. The amoeba when first noticed was already elongate, and 

 the dividing nucleus appeared as a refractile streak across the body of the parasite. 

 A similar dividing form (Fig. 62) was once seen in a fixed and stained preparation. 

 The nucleus was drawn out in the form of a long spindle with a central fibre, which 

 opens out at its extremities into cone-like expansions, perhaps composed of the 

 remains of the fibres of the nuclear spindle. The actual ends of the dividing 

 nucleus were composed of chromatin masses or plates (Fig. 62). The division of 

 the cytoplasm was delayed somewhat after that of the nucleus. 



Encystment was rarely seen in life, and the full details could not be followed. 

 It was noticed sometimes that, following division, the daughter individuals pro- 

 ceeded to encyst after a short interval, and so formed small cysts. In fixed prepara- 

 tions somewhat small uninucleate cysts, about 12^ to 14^ in diameter, were seen 

 (Fig. 64). Larger cysts containing four nuclei were also found (Fig. 65), but the 

 cysts were not numerous. The larger cysts measured about 20^ in diameter. 



I am sorry that opportunity did not arise for me to make an extended study of 

 this parasite. 



Although Entamceha histolytica (Schaudiun) is the pathogenic agent of a form 

 of dysentery in man, it is not very likely that Amceha {Entamceha) lagopodis is the 

 cause of such a serious disease in Grouse, but A. lagopodis is more like Entamceha 

 coli, which is usually considered to be a well-nigh harmless parasite in the human 

 intestine. 



Amceha meleagi'idis (Theobald Smith, 1895), which has been associated with 



