On the Caucarteous Corpusciss of the TrEMatopa; and on 
the GENUS Terracotyte. By HE. Cuaparepe, of Geneva. 
(Siebold and Kolliker’s ‘ Zeitsch. f. w. Zool.,’ vol. ix, p. 99.) 
Tuer calcareous corpuscles of different entozoa have fre- 
quently attracted the attention of observers. For a long time 
regarded as ova, their calcareous constitution was at length 
recognized, and at present they are universally looked upon 
as an earthy deposit in the integument. Siebold, for instance, 
compares them with the calcareous bodies found in the in- 
tegument of the Holuthuriz and in the soft parts of many 
polypes. I have, however, for some time, been aware that 
these corpuscles, in some Trematoda at any rate, have a cer- 
tain relation to the excretory apparatus. This observation 
was first made in April, 1855, in Diplostomum rachieum, 
Henle, from the spinal canal of the Frog. In this instance, 
it was obvious at first sight that a minute vessel proceeded 
from each corpuscle. Closer examination showed that each 
corpuscle is contained in a capsule fitting pretty closely 
around it, and whose wall is continuous with that of the 
tubule. Several of these vessels unite into a single branch, 
which communicates again with one of the ramifications of 
the excretory system. This system in D. rachieum is con- 
stituted of a slender, gradually enlarging trunk, which runs 
from behind forwards in the middle line of the body, and 
is connected, at the anterior extremity of the animal, by 
a branch on either side, with the lateral trunks. The latter 
descend nearly parallel with the border and, gradually en- 
larging, open at the hinder end into the two-pointed 
contractile vesicle. From each of these three main trunks 
numerous vibratile vessels are given off; and besides these 
they are connected with each other by numerous transverse 
branches; one of which, in particular, may always be re- 
marked passing across immediately in front of the abdominal 
acetabulum. As is well known, Leydig* has regarded this 
excretory system as a ramified intestine, considering, on the 
other hand, the true intestine as a bifureate excretory ap- 
paratus. 
ach ramuscule terminates ciecally, becoming expanded 
ito an oviform vesicle, uniformly occupied by a calcareous 
corpuscle. These bodies, however, are never met with in the 
* «Zeitschrift fir Wissensch. Zool.’ 
