Miscellaneous. 495 



On the contrary, after a series of observations upon the most diffe- 

 rent objects, I have arrived at the conviction that this view is 

 erroneous. I have succeeded in demonstrating the following facts : — 



1. The vessel-like dilatation of the canals of the caudal setae in 

 the last abdominal segment is directly connected with the dorsal 

 vessel. During the contractions of the heart it receives a portion of 

 the blood which may be in the hindmost division of the vessel, and 

 which it then by its own contractions drives into the canals of the 

 caudal setse. 



2. A communication of this vessel with the body-cavity, so as to 

 permit the entrance of blood into it in accordance with the above- 

 mentioned opinion of Verlooren's, I have been unable to observe. 

 There rather seems to me to be a firm union with the dorsal 

 vessel. 



3. The valvular apparatus situated at the anterior end of the 

 vessel consists of two membranes parallel to the plane of symmetry 

 of the body, which, as processos of the dorsal vessel, are directed 

 backwards and attached in an inversion of the vessel. 



4. These membranes, like the other valvular apparatus of the 

 dorsal vessel, are set in motion by its action, only in the opposite 

 way. They apply themselves together when the dorsal vessel ex- 

 pands, and open when it contracts, by which of course a flow of 

 blood directed from before backwards is produced. 



The latter fact is probably the best proof of the untenability of 

 Verlooren's opinion. For if the vessel were to be furnished with 

 blood from the body-cavity by the action of the valvular apparatus, 

 the movement of the membranes must have stood in some relation to 

 the phenomena of contraction of the vessel, which, however, is by 

 no means the case. 



On the other hand, scarcely any argument can be brought against 

 the proposition established by me ; on the contrary, we may easily 

 convince ourselves by direct observation of the correctness of my 

 statements. — Zool. Anzeiger, April 27, 1885, no. 193, p. 246. 



On the Existence of a Nervous System in Peltogaster ; a Contribution 

 to the History of the Centrogonida. By M. Y. Delage. 



Until quite recently the Centrogonida (Rhizocephala of Fritz 

 Muller) were regarded as destitute of a nervous system. In a 

 communication to the Academy *, and, more recently, in a more 

 extended memoir f , I have shown that the nervous system exists in 

 Sacculina. After this it was almost certain that it existed also in 



* ' Oomptes .Rendus,' tome xcvii. (October 29, 1883). 



t " Evolution de la Saeculine, Crustace' endopavasite de l'Ordre nou- 

 veau des Kentrogonides," Archives de Zool. expe>. se>. 2, tome ii. 1884. 

 [We do not see why Fritz Midler's name Rhizocephala was ri'ot retained 

 for the new order; but, while accepting the new name, we shall not dis- 

 figure the pages of the ' Annals ' by adopting the anther's barbarous 

 spelling.] 



