Enteritis in Native Animals. '439 



the wallaby, but the fact that in serial sections each cyst is 

 found to be definitely associated with one of these masses, and 

 that they are always in the same situation negatives such a 

 view. 



In the early stages the blastophore or schizont appears as a 

 faintly staining space (12.8/>t to 15/x, in diameter) crowded 

 with nuclei (1.7/x in diameter), and surrounded by endoplasm. 

 As the parasite increases in size these nuclei multiply greatly, the 

 cell nucleus becoming definitely pushed to the pole furthest from 

 the centre of the group. The nuclei of the parasite are at times 

 seen arranged around a central mass mulberry fashion, but often 

 no such arrano-ement is distinct. Gradually they become sur- 

 rounded by a spindle-shaped mass of faintly-staining protoplasm 

 with blunt ends, and no definite markings, attaining in size 

 4.3/x to 4.7)a long, by 1.7/x to 1.9/x broad. In none of our 

 sections are the spores of these large cysts seen to be mature, and 

 there is no evidence of rupture. 



Small Cysts. Lymphocystis macropodis. 



(Although for purposes of description these are here so termed, 

 we recognise that the parasites in question cannot, strictly 

 speaking, be classed as " cysts.") 



All the villi in our sections, as already stated, are greatly 

 swollen, and almost all are denuded of epithelium. The majority 

 are crowded especially towards the base with large cells 8.4/x 

 in diameter, containing parasites, which have pushed the nucleus 

 to one side (Plate LXX VIII., Fig. 13). In these parasites nearly all 

 the stages of schizogony, from that of division into four nuclei, 

 can be observed, although rarely in the one field. Plate LXXIX., 

 Fig. 14, shows the various stages as observed, drawn under the 

 camera lucida. The nucleus soon after invasion of the cell by 

 the parasite becomes enlarged and pushed towards the periphery. 

 In the earliest stage of the parasite we have observed, viz., with 

 four nuclei (1.7/x in diameter), the cell nucleus tiiough enlarged is 

 but slightly eccentric. When situated at the very edge, the 

 nucleus may seem at first sight irregular, but careful focussing 

 demonstrates it to be saucer-shaped and clasping the cell. As 

 the parasite grows, the nuclei multiply, and the schizont gradu- 



