GENEEAL ORGANIZATION 771 



lleocystis tnacropodis, and the smaller one Lymphocystis macropodis. A large 

 one in the wombat {Phascolomys latifrons) was called /. wombati. Believing 

 the form in the wallaby {Petrogale sp.) to be a sarcosporidian, they gave it 

 the name S. macropodis. The large cysts, which were named I. wombati, 

 had thick walls, and reached a diameter of about 93 to 113 microns. In 

 structure they resembled G. gilruthi. The smaller cysts, named L. macro- 

 podis, occurred in the connective tissues of the mucosa in large numbers. 

 When mature, they had a diameter of about 8-4 microns and were filled 

 with spores. The cyst wall was merely a membrane, which appeared to 

 consist of the remains of a mononuclear cell, the nucleus of which could be 

 detected as a flattened structure at one side. It is possible that L. macro- 

 podis is really a small form of I. macropodis, in which, however, free spores 

 were not seen, though stages showing many nuclei and what appeared to 

 be commencing spore formation occurred. The parasite called S. macro- 

 podis was also in the mucosa, measured 150 to 700 microns in diameter, 

 and was filled with spores. It appears to be a species of Globidiuyn, though 

 Chatton (1912c) has suggested placing it in a new genus, Haplogastrocystis. 

 Recently the writer and Scott (1925) and Triffifct (1926) have seen in the 

 wallaby {M. bennetti) parasites like /. macropodis and L. macropodis. It 

 was not possible to determine whether the smaller form was actually of the 

 same species as the larger one, though this would seem not improbable. 

 The whole of the connective tissue of the mucosa was filled with the 

 smaller parasite, while numerous free spores were scattered between the 

 cells. In addition, the muscle fibres of the intestine contained elongate 

 vacuolic spaces filled with spores, which appeared very similar to those of 

 the parasite of the Lymphocystis type. Whether this parasite, again, is 

 a species of Sarcocystis or is another stage of Lymphocystis could not be 

 decided. If three parasites are represented, then in this portion of the 

 intestine there occurred four distinct species, as an Eimeria was present in 

 the epithelium. It is possible that the parasite described by Blanchard 

 (1885) and named S. mucosce is identical with /. macropodis. Cunha and 

 Torres (1924) record a species {G. tatusi) found by them in the armadillo. 

 The structure of the cysts of G. gilruthi of the sheep and goat was 

 described in detail by Chatton (1910). The cysts have a diameter of 

 200 to 500 microns, and are situated within little opalescent elevations of 

 the mucosa (Fig. 331, i). Each is enclosed by a definite wall, which has 

 concentric striations. At one place in the wall there is a large flattened 

 nucleus, which may be 80 microns in length by 10 in breadth (Fig. 331, 2). 

 According to Chatton, the cyst wall represents the remains of a very much 

 hypertrophied and altered cell which may be connected by a kind of neck 

 with the connective tissue. Within the mature cyst is a mass of spores, 

 each of which measures 10 by 1-5 microns (Fig. 331, 7). One end is blunt 



