INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 955 



Can we fiutl in the anal vesicles of the Gephyrea a resemblance to 

 the excretory organs of the Rotifera ? The investigations of Lacaze- 

 Duthiers on Bonellia viridis have shown that there are two large 

 contractile vesicles opening into the cloaca ; into these vesicles open 

 tufts of ramified tubes which open by their end into the coelom by 

 ciliated iufundibula ; the author remarks that in Echiurus this 

 arrangement is less well developed,* and that in Sipunculns it is 

 reduced to the rudiments of the vesicles. On the other hand, Sipun- 

 cnliis has a pair of true segmental organs, while Bonellia has none at 

 all. In Thalassema and the Echiurida there are two or three pairs of 

 segmental organs. 



In the Hirudinea the primitive excretory apparatus seems, at least 

 during development, to make a last appearance, while it completely 

 disappears in the Annelidcs. Are the permanent renal organs of 

 these Annulata the homologues of the apparatus found in the more 

 lowly worms? This does not seem to be yet certainly established, 

 for we have (1) the presence of both sets of organs in some adult 

 Gephyrea, and (2) in the Hirudinea the two sets, one of which dis- 

 appears very early, appear to have an independent origin. 



Tlic author is not inclined to accept Professor Haeckel's division of 

 the Vermes into Ccelomati and Acoelomati ; as to the latter, he points 

 out that there are spaces in tlie connective tissue of the Trematoda, 

 and that into these the ciliated infundibula open ; these lacunae may 

 further vary greatly in extent ; this is true of the terrestrial Planaria, 

 where Moscley has discovered longitudinal s^^aces on either side of 

 the body, and of the Nemertiuea, where a ccelomatic space has been 

 observed by Macintosh and Hubrecht to surround the digestive 

 tract. 



In a note presented to the Academy of Brussels,! M. Fraipont 

 states that he has been able to extend his observations to Distomum 

 appendiculatum (which lives in the intestine of Gadus morrhua), and 

 finds it to be provided with ciliated infundibula, exactly comparable 

 to those of D. S(iunmida. D. divtn/cns has, it is interesting to note. 

 two infundibula terminating each canaliculus, and that in the place 

 of one. A young living Tienia echinococcus has, in addition to the 

 four longitudinal canals, a system of fine canaliculi, a certain number 

 of whicl) terminate by small ciliated infundibula, similar to those of 

 T. serrat a and T. cucumcrina. Bothriocepludus infundihuUformis (from 

 the pyloric ai)pendages and intestine of Trutta trutta) has a very 

 complicated system of canals. Tricuspidaria nodulosa (from the 

 intestine of Esox lnrian) has a plexus of very fine canaliculi, from 

 which there arise small branches which are j)rovided at their free end 

 with a ciliated infundibuluni. 



Ciliated Embryo of Bilharzia.:}: — The ovum of this little-studied 

 entozonn presents, according to ]M. J. Chatin, a regularly oval shape, 

 and a smooth external contour, and has a conical prominence at one of 

 its poles. Segmentation is rapid, and results ultimately in the forma- 



* Sec t1lis Journal, .ni/r. p. \'M. 



t • Hull. A.ad. K. Sci. IJfl- ,' xlix. (1880) p. lOG. 



i 'CoinptcH Ucn.lu.s,' xci. (1880) p. 554. 



