ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 279 



S. edentatus ; and (2) Gylicostomum adersi sp. n., presenting much the 

 same appearance as G. insigne. J. A. T. 



Development of Strong-ylacantha glycirhiza. — L. G. Seurat 

 {Gomptes Rendus Soc. Biol., 1920, 83, 1172-4). The ovum of this 

 Nematode, a parasite of the small intestine of Rhinolophus, is elliptical, 

 opaque, rich in jolk. It divides into a large clear anterior blastomere 

 (initial somatic) and a much smaller posterior blastomere, opaque, and 

 with much yolk (the primordial sex-cell). The latter divides into a 

 meso-endodermic-stomodffial cell and a primordial sex-cell. The larva 

 is remarkable in showing three distinct cuticles, a buccal cavity without 

 trace of the adult hooks, an excretory pore far from its final anterior 

 position, and a genital primordium of four cells. It does not feed ; it 

 moults twice ; it becomes encysted ; and in this state it passes from the 

 foul soil of the grotto into the definitive bat host. The intestine 

 remains very embryonic, consisting of two rows of very large cells with 

 a narrow central space between. J. A. T. 



Revision of Gnathostomidae. — H. A. Baylis and Clayton Lane 

 {Proc. Zool. Soc, 1920, 24,5-310, 8 pis., 40 figs.). The chief charac- 

 teristic of this family of Nematodes is the possession of a pair of large, 

 fleshy, trilobed, lateral lips. Each lip is provided externally with three 

 papillffi, while internally its cuticle is thickened and frequently raised 

 into tooth-like prominences in the form of longitudinal ridges, which 

 either meet or interlock with those of the other lip. The oesophagus is 

 of a simple club-shaped type. There are two cervical papilla, usually 

 not prominent, in both sexes, and the tail of the female is provided with 

 a pair of small lateral papillge. The male has more or less well-developed 

 caudal ala? and two spicules, usually ornamented. Most species are 

 found in the anterior part of the alimentary canal, with a tendency to 

 burrow. One genus {Gnathostoma) has been found as a rare, and 

 probably abnormal, parasite of man, its habitat being the subcutaneous 

 connective tissue. The genera of the sub-families G-nathostominte and 

 Spiroxyinaj are dealt with in detail. J. A. T. 



Platyhelminthes. 



Studies on Bilharziasis. — Philip Manson-Bahr and N. Hamil- 

 ton Faieley {Parasitology, 1920, 33-71, 3 pis., 3 figs.). A discussion 

 of the differences in structure and life-history between the two species 

 of Egyptian Schistosomidje— Schistosomum hsematobium and S. mansoni. 

 The former has terminal spined ova which are deposited in both urine 

 and fffices. The ciliated miracidium hatched out in the watei' must 

 find the correct species of Bidlinus in thirty-six hours. It pierces the 

 soft parts, probably in the pulmonary chamber, and reaches the digestive 

 gland and the gonads. It becomes a morula, which is hollowed out 

 into an elongated finger-like sporocyst. This gives rise, by internal 

 budding of " germ balls," to cercarise ; and there may also be exogenous 

 budding resulting in secondary cysts. When mature, the cercaria^ are 

 ejected into water, and in the subsequent twenty-four hours must find 

 their way into their definitive host, usually man. After invading the 



