806 Mr. F. E. Beddard. On a new Form of [Mar. 



the adiabatic relations for liquid and gaseous ether: the rise 

 pressure and temperature when volume is 'decreased without escaj 

 of heat. It is obvious that similar relations are determinable for 

 solutions, and probably with much greater facility. M. Alexeeff has 

 made some measurements which might be utilised for this purpose ; 

 but they are far too few in number, and, moreover, the necessary- 

 data as regards osmotic pressure are wholly wanting. It would be 

 possible by a series of differential experiments to ascertain the 

 evolution of heat on increasing concentration, and so to arrive at a 

 knowledge of the speci6c heats of the solution at constant osmotic 

 pressure, corresponding to the idea of specific heat at constant 

 pressure ; and also of specific heats at constant concentration, corre- 

 sponding to specific heats at constant volume. I do not know 

 whether such researches would yield as accurate results as those wej 

 are at present carrying out, but they are at least well worthy of 

 attention. 



1 1. " Preliminary Notice of a New Form of Excretory Organs it 

 an Oligochsetous Annelid.". By FRANK E. BKDDARD, M. 

 Prosector of the Zoological Society. Communicated 

 Professor E. RAY LANKESTER, M.A., LL.D., F.R.J 

 Received February 19, 1891. 



So far as our knowledge of the Oligochaeta goes at present, 

 excretory system appears to consist either of one or more pairs 

 separate nephridia in each segment, or of a diffuse, irregularlj 

 arranged system of tubules with numerous external pores upon 

 segment, and often with numerous ccelomic funnels in each segment 

 there may or may not be a connexion between the tubes of success^ 

 segments. All the aquatic Oligochaeta have nephridia of the 

 kind ; a large number of the terrestrial Oligochaeta have nephridia 

 the second kind ; there is occasionally in the latter forms a specialie 

 tion of part of the diffuse nephridial system into a pair of Is 

 nephridia ; these species connect the two extremes. But in all tht 

 Worms the nephridia are contained in the ccelom, though some of tl 

 connecting branches may be retroperitoneal ; the ducts which lead 

 the exterior may branch in the thickness of the body wall, but tl 

 does not seem to be any extensive ramification and anastomosis of the 

 tubes in the muscular layers of the body wall.* 



I have recently found a remarkably different arrangement of the 

 nephridia in an Annelid belonging to a new genus of Eudrilidae. 

 This family is chiefly noteworthy on account of the remarkable modi- 



' Quart. Journ. Micr. Sci.,' vol. 28, PI. XM, fig. 1, n, and fig. 2. 



