316 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
of Distomum of which he, with Mr. Hassall, has given an account in the 
£ Veterinary Magazine 5 of Philadelphia. D. tricolor has been found in 
Lepus sylvaticus and L. americanus. It is very common in Maryland, 
Colombia, and Virginia. It is intermediate in structure between the 
genera Mesogonimus and Urogonimus. Like Braun and other authors, the 
present writers have doubts as to the validity of these two genera. 
Self- copulation has been observed in this new species. 
Distomum molle.* — The same authors report that the species which 
the late Prof. Leidy called Monostomum molle is a Distomum , most 
closely allied to D. polyorchis (Stossich). They give a short description 
of the species, and point out its resemblances to, and its differences from, 
Stossich’s species. The characters are such as to justify the formation 
of a sub-genus (Poly orchis) and probably even of a genus. 
Distomum gigas.j — Sig. E. Setti gives an account of an example 
of this species, which was observed in the fresh condition, when 
it measured 12 cm. long. In a transverse section the body was seen 
to be bounded by a cuticle and subcuticular layer, as well as by a 
basal membrane. The oesophagus is short, and the two intestinal trunks 
are unbranched. The excretory vesicle is small and receives two long 
primary trunks. The generative orifice is on the ventral surface, and 
lies midway between the two suckers. The uterus extends backwards 
to about 2 cm. from the end. The ova are O’ 0335 mm. long and O' 030 
mm. broad. 
Early Stages in the Development of the Taeniae of the Rabbit4 — 
Dr. C. W. Stiles, in examining rabbits for the purpose of finding 
Distomum tricolor , found in the intestine several very small tape-worms. 
They varied from 0*624 mm. to 0*96 mm. in length, and had not yet 
commenced to form rings. While many specimens presented nothing 
remarkable, and had heads similar to those of ordinary unarmed 
Anoplocephalians, several presented characters which deserve a special 
description. The orifice of their suckers was provided with numerous 
and very small hooks of which there may have been as many as 150 or 
200 to each sucker. The tip of the head was provided with a retracted 
rostrum, the equator of which was occupied by a row of small hooks. In 
several specimens the anterior portions of the head and neck were covered 
by a membrane. The small hooks and the membranous envelope were 
merely temporary structures which disappeared in a short time, and left 
the head with the characteristic appearance of the Anoplocephalinae. 
A further account is promised. 
Tetrarhynchi.§ — Dr. Th. Pintner continues his investigation of these 
most highly differentiated Cestodes. He differs from Lang on three 
essential points. (1) The proboscis-muscles, arranged in interlocked 
layers, are cross-striped, and in the interior of the prismatic muscle- 
bands is a fibrillar plasma. The latter Lang regards as a nerve, and he 
describes the muscle-fibres as smooth. (2) Pintner described very 
peculiar large cells — formative epithelial cells — in a double row alongside 
* Bull. Soc. Zool. France, xix. (1894) pp. 162-3 (1 fig.). 
t At. Soc. Lig. Ann., vi. (1894) 19 pp. (1 pi.). See Zool. Centralbl., i. (1895) 
pp. 828 and 9. J Bull. Soc. Zool. France, xix. (1894) pp. 163-5. 
§ SB. Akad. Wiss. Wien, cii. (1893) pp. 605-50 (4 pis.). 
