76 SUMMARY OF CURRENT RESEARCHES RELATING TO 



have lost their protoplasmic contents. A fully matured psorosperm has 

 a fine hyaline envelope, with one or two nuclei, inclosing a thick 

 chitinous capsule, within which is a spherical mass of protoplasm. The 

 best preparations obtained were those which were treated with osmic 

 acid or stained with picrocarmine. 



Coccidium infesting Perichseta.* — Mr. F. E. Beddard gives the first 

 account of a Coccidium living in an earthworm. The forms in which 

 they have been found are Perichseta novse-zealandise and P. armata ; the 

 perivisceral cavity was the part infested ; some individuals were, in form, 

 hardly distinguishable from G. oviforme, but the " micropyle " is very 

 different. This so-called micropyle does not seem to be a perforation of 

 the cyst at all, but merely a bulging-in of the cuticle, due possibly to a 

 separation of part of the internal cuticular lamella caused by reagents. 

 Sometimes two of these structures are present. The outer cyst-membrane 

 does not, as in C. oviforme, disappear, but increases greatly in import- 

 ance, until it finally comes to project beyond the two poles of the cyst 

 for a very considerable distance; it still, however, remains very 

 transparent. 



The contained protoplasm breaks up into a large number of sporo- 

 blasts, just as happens in the Gregarinidse, and this fact, added to others, 

 shows that there is a closer affinity than is generally supposed between 

 the Coccidiidae and the Monocystidae. G. pericJisetse also resembles 

 certain of the latter, e. g. Gamocystis, in the great development of the 

 outer cyst-membrane. 



Sarcosporidia in Muscles of Palsemon.t — M. L. F. Henneguy de- 

 scribes from the muscles of Palsemon redirostris a parasite which seems 

 unquestionably allied to the Sarcosporidia hitherto only known in 

 mammals. The muscles weve white and opaque instead of being trans- 

 parent ; the fibres were full of clusters of granule-like bodies. Each 

 granule usually contained eight small corpuscles, presumably spores. 

 The parasite was only distinguishable from the Sarcosporidia of mammals 

 in the envelope which surrounded the several clusters of granules. All 

 the specimens of Palsemon examined had the parasite in the same stage ; 

 infection was tried but failed. The life-history remains, therefore, in 

 Palsemon, as elsewhere, obscure. The disease appeared to limit the 

 muscular power. The diseased forms were usually in sheltered and 

 warm water. Other species were observed to be similarly affected 

 — P. squilla, P. serratus, and Palsemoneies varians. M. Henneguy dis- 

 tinguishes the Sarcosporidia from Psorospermium haecJcelii, from parasites 

 of some Daphnids, and from some strikingly similar granules found in 

 Gohius. The present form seems to come in between Microsporidia and 

 Myxosporidia, but the author refrains from a verdict till the life-history 

 of this and similar forms has been made out. 



Cercomonas intestinalis.l — Prof. E. Perroncito finds that guinea- 

 pigs are infested by numerous varieties of Gercomonas of which there 

 are three principal species, (1) G. ovalis, (2) G. pisiformis, (3) G. glohosus. 

 The last two kinds are so numerous in a certain disease of these rodents 

 as to become the cause of a great mortality among these animals. 



* Ann. and Mag. Nat. Hist., ii. (1888) pp. 433-9. 



t Mem. Centenaire Soc. Philom., 1888, pp. 163-71 (1 fig.). 



J Centralbl. f. Baktcriol. u. Parasitenk., iv. (1888) pp. 220-1. 



