1888.] Mr A. E. Shipley, On the Vascular System. PAILS} 
May 7, 1888. 
Mr J. W. CLARK, PRESIDENT, IN THE CHAIR. 
J. B. Hott, B.A., Christ’s College, was elected a Fellow of the 
Society. 
The following communications were made: 
(1) On the Existence of Communications between the Body- 
cavity and the Vascular System. By ARTHUR EK. SHIPLEY, M.A. 
In the General Considerations which follow Mr Sedgwick’s 
recent paper upon the development of Peripatus Capensis, he sums 
up the characteristics of the coelom in the following terms: (i) the 
coelom does not communicate with the vascular system; (11) it 
communicates with the exterior through nephridial pores; (111) its 
lining gives rise to the generative products; (iv) it developes either 
as one or more diverticula from the primitive enteron, or as a 
space or spaces in the unsegmented or segmented mesoblastic 
bands (in the latter case called mesoblastic somites). Later on 
he calls attention to the fact that “there are certain animals to 
which the above general considerations as to the distinctness of 
the coelom and the vascular system do not apply.” The animals 
here referred to are the Hirudinea and the Nemertea. In a later 
paper Sedgwick suggests the possibility that the nephridial 
funnels of Leeches might possibly open into a closed vesicle which 
lies in, but does not open into the vascular system. That some 
such structure may have been overlooked is rendered more 
probable when one recalls: the number of able observers who failed 
to observe similar structures in Peripatus, and the fact that so 
careful a worker as Oscar Schultze overlooked the comparatively 
large nephridial funnels, when working at the excretory system of 
Clepsine. 
Last term I devoted some time to the examination of these 
points. The forms I investigated were Clepsine, and to some 
extent Pontobdella amongst the Rhyncobdellidae, and amongst 
the Gnathobdellidae, Hirudo and Nephelis, and I may as well say 
at once that my researches on these forms confirm the results 
which Bourne published in the year 1884 in his exhaustive paper, 
19 
“Contributions to the Anatomy of the Hirudinea’, 
1 Quarterly Journal of Microscopical Science, Vol, xx1v. p. 419. 
