326 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
organs, open at either end; the proximal end bores through the dis- 
sepiment of tlie next anterior segment, and the external orifice is at the 
tip of a neurally placed seta which corresponds to the hinder edge of its 
segment. In every nephridium there may be distingnished the funnel, 
the internal ascending nephridial loop, the sac, the outer loop, and the 
papilla. There is only one pair in a segment, and each nephridium has, 
contrary to Haswell’s statement, only one outer orifice. These organs 
are found in all the segments except the first four and the last ; they 
differ in structure in different segments, and those of the right side 
exhibit some differences from those of the left. The form of the anterior 
nephridia and of all in the young is the same ; and this form is the 
primary one ; that of the hinder nephridia and that seen during sexual 
maturity is a secondary one. The organs consist of two cell-layers, an 
outer which is peritoneal and an inner which is epithelial ; the several 
form-elements of the latter appear to be ciliated cells, but they vary 
somewhat in character in diflerent regions of the organs. 
There have been many discussions as to the functions of these 
structures; Herr Trautzsch acknowledges that they have renal func- 
tions, and that this is primary ; the anterior simpler nephridia have no 
other. The hinder tubes cease to be renal during the period of sexual 
activity, when they take on as a secondary duty the office of conveying 
sperm or ova ; or, in other words, they undergo a change of function. 
At the same time the generative products are not driven to the exterior 
by the activity of the^ nephridia, but chiefly by contractions of the 
surrounding muscles. 
New Genus of Oligochaeta.* — Prof. A. G. Bourne describes a new 
worm, CJisetohrancJius, found in mud from a pond in Madras town. The 
worm attracted him by its branchial processes, which could be seen 
with the naked eye. The most remarkable feature is the presence of 
dorso-lateral processes, of which there is a pair to each of the anterior 
segments; they are obviously branchial in function. Each is virtually 
a hollow prolongation of the body-wall ; the ep>idermis is bounded 
externally by a distinctly visible cuticle, through which very fine cilia 
project ; at the extremity are a few stiff processes which are doubtless 
sensory in function. Into each of the longer processes (about the first 
fifty) there runs a loop of the lateral vessel. 
Entirely contained within each process are the processes of the seta&, 
all in the case of the more anterior, or some in that of the more posterior, 
which belong to the dorsal bundle ; there are no muscular structures in 
the branchial processes, which are kept fairly rigid, are moved by the 
dorsal setae, and thus serve the worm as locomotor organs. There seems 
to be no doubt that this worm has been noticed by Semper, and the 
author proposes to call it CJisetohrancJius Semperi. 
Anatomy of Dero-t — Mr. F. E. Beddard has some notes on the 
anatomy, chiefly of the reproductive organs, of a species of Dero 
(H. perrieri), found by Messrs. Bolton, of Birmingham. There can be 
no doubt that this annelid has been correctly referred to the Naido- 
morpha, but it has not genital setae on the sixth segment. 
* Quart, Journ. Micr. Sci., xxxi. (1890) pp. 83-9 (1 pL). 
t Proc. Zool. Soc. Loud., 1889 (1890) pp. ■110-4 (3 figs.). 
