524 SUMMAKY OF CUEEENT EESEAECHES RELATING TO 



currents enter respectively the right and left branchial chambers. The 

 epistomial ridge on the roof of the prostomial chamber turns aside some 

 portion of the in-current, which portion passes out ventrally thi'ough a 

 gap in the floor of the chamber, carrying out with it foreign particles 

 brought in by the in-current and rejected by the sieves guarding the 

 entrance to the branchial chambers. 



New Hersilia.* — Kathleen Haddon describes Hersilia {Clausidium) 

 vancouverensis sp. n., a small Copepod which occurred in vast numbers 

 in the gill-chambers and also all over the body of many specimens of 

 Gallianassa pugettensis collected on the beach near Nanaimo in Vancouver 

 Island by Mr. F. A. Potts. They were conspicuous on account of the 

 bright red colour of the egg-sacs. They alternated between a state of 

 quiescence, during which they were attached to the surface of the host, 

 and rapid jerky movements made when disturbed. The tiny male was 

 attached to the tail of the female in almost every case. The new species 

 is carefully compared with Hersilia {Clausidium) apodiformis (Philippi) 

 from Callianassa subterranea in the Mediterranean and Adriatic. 



Annulata. 



Blood of Arenicola.t — E. Peyrega has used spectroscopic methods in 

 order to determine whether the red pigment of the blood of the lobworm 

 is really htemoglobin. Taking precautions to get the blood pure, without 

 any of the green pigment which the animal secretes, she compared it in 

 detail with that of the horse, and found that there were only minimal 

 differences. 



Nematohelminthes. 



Degenerative Parthenogenesis in Ascaris megalocephala.J — E. 

 Faure-Fremiet points out that in the germinative zone of the gonads 

 there is a degeneration of a certain number of '' gonia." This occurs in 

 two ways — ^(1) The gonia may degenerate in situ into " residual cor- 

 puscles " ; or (2) they may pass prematurely beyond the germinative 

 zone into the seminal ampulla or into the uterus. The male gonia that 

 fall prematurely into the seminal ampulla do not show any important 

 changes ; their nucleus fragments into 2 to 4 parts. But the oogouia 

 that are prematurely detached form pseudo-embryonic groups of cells 

 with a central cavity, which are probably expelled or absorbed. The 

 parthenogenetic segmentation which leads to the formation of these 

 pseudoblastulge is not at all like the normal segmentation. It is what 

 Henneguy has called " degenerative parthenogenesis." 



Metabolism in Development of Ascaris megalocephala.§ — E. Faure- 

 Fremiet has studied the development of the egg from the chemical side. 



♦ Ann. Nat. Hist., x. (1912) pp. 84-6 (1 pL). 



t Comptes Rendus, cliv. (1912) pp. 1732-4. 



X Comptes Rendus, civ. (1912) pp. 365-6. 



§ Bull. Soc. Zool. France, xxxvii. (1912) pp. 233-4. 



