1010.] PARAslTIf l'K(;:(!/.()A OF ItlCU C.'liCUSF.. 703 



seen in tlie form of granules (ing. 58). The whole nucleus, however, 

 is somewhat [loor in chroniMtin, tliough a kaiyosome may he 

 present (figs. 58, 60, 63) as before-mentioned. 



Division by binary fission was seen once in life, the process taking 

 about thii'ty minutes for completion. 1'he Amoeba when first 

 noticed was ah'eady elongate and the dividing nucleus appeai'ed 

 as a I'efi'actile streak aci-oss 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 tibi-e, which opens out at its extremities 

 into cone-like expansions, perhaps composed of the I'emains 

 of the fibres of the nucleai- spindle. The actual ends of the 

 dividing nucleus were composed of chromatin ma^sses or plates 

 (fig. 62). The division of the cytoplasm was delayed somewhat 

 after tha.t 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 proceeded to encyst after a 

 sh.oi't interval and so formed small cysts. In fixed piepai'ations 

 somewhat small uninucleate cysts, about 12 ^ to 14/i in diameter, 

 were seen (fig. 64). Largei- cysts containing four nuclei were 

 also found (fig. 65), but the cysts were not numerous. The 

 lai'ger cysts measuied about 20 ^i in diameter. 



I am soiiy that opportunity did not arise for me t«> make an 

 extended study of this pai-asite. 



Although Entaiatvha histolytica (Schaudinn) is the pathogenic 

 agent of a foi-m of dysenteiy in man., it is not very likely that 

 Amoeba [Evtamoeba) lagopodis is the cause of such a serious disease 

 in grouse, but A. lagopodis is more like Entamoeba colt, which is 

 usually considered to be a well-nigh harmless parasite in the 

 human intestine. 



Amiieba meleagridis (Theobald 8mith, 1895), which has Ijeen 

 associated with the disease known as " blackhead " in tin-keys, is 

 now generally considered to be a stage in the life-liistoiy of a 

 ('occi(lii(m. 



(d) Sporozoa— Gregrarinida. 



MONOCVSTIS Sp. 



Spores of a Gregarine, almost certainly a species of Monoa/stis, 

 Avere occasionally found in the contents of the gut of a few grouse 

 from the Lowlands of Scotland and the North of England. The 

 spoi-es present much the same featuies as those commoidy 

 occurring in the Earthworm, and show the same pseudo-navicellar 

 appearance. The spores seem to pass through the alimentaiy 

 canal of the grouse intact. The grouse acquiie the spores 

 accidentally by way of their food (though earthworms are not 

 common on many grouse mooi's), and the spores have no ill efi'ect 

 on the birds. Probably the internal heat of the bird's body aids 

 in the de\elopment of the sporozoites within the sporocysts, 



46* 



