394 SUMMARY OF CURRENT RESEARCHES RELATING TO 



right side instead of on the left. In other respects also the larva was 

 a perfect mirror-image of the normal larva. They developed normally, 

 and the young urchins were externally normal. Tlie interesting point 

 is the recovery of the left hydrocoele. MacBride and Ohshima attribute 

 the development of two hydrocoeles to a latent power in the right 

 anterior ccelom developing a hydrocoele, a power which is normally 

 inhibited by the development of the functional hydrocoele from the left 

 anterior coelom. MacBride regards the latent power of the right side 

 as an indication of ancestral bilaterality. Ohshima finds the explana- 

 tion in homocosis. J. A. T. 



Ccelentera. 



Luminescence of Renilla. — G. H. Parker {Pror,. Amer. Phil. Soc, 

 11)20, 19, 171-5). Louis Agassiz observed that Renilla reniformis 

 " shines at night with a golden green light of a most wonderful soft- 

 ness." This is also true of R. amethystma of southern California. At 

 night the stimulated colony glows with a wonderfully clear blue-green 

 light. There is probably a rhythm in the animal's metabolism, for the 

 luminescence induced by day never reaches the degree of brightness 

 seen at night. The luminescence is induced by mechanical or electrical 

 stimulation. Luminous ripples emanate from the spot stimulated (on 

 the upper surface) and spread out concentrically over the disc, like waves 

 on the smooth face of a pond into which a pebble has been thrown. 

 The luminescence is limited to light-coloured material surrounding the 

 bases of the zooids on the upper surface. This light-coloured material 

 consists of a whitish chalky substance and a light-yellowish one, the 

 former being the photogenic substance. The impulses that induce the 

 luminescence are profoundly influenced by such anajsthetics as mag- 

 nesium sulphate. It seems that the transmission of the phosphorescent 

 waves is neurogenic rather than myogenic ; its rate varies with the 

 temperature ; it is probably due to chemical rather than to physical 

 processes. J, A. T. 



Porifera. 



Irish Sponges. — Jane Stephens (Fisheries Ireland, Sci. Invest., 

 1921, 2, 1-75, G pis.). An account of the Tetraxonida of the sub-order 

 Si2:matomonaxonellida found on the coasts of Ireland. There are 

 descriptions of thirteen new species, the majority of which have been 

 found growing on coral (chiefly Lojjhohelia prolifera) in deep water. In 

 one haul 37 species of sponges were obtained (5 Tetractinellida, 30 

 Monaxonellida, and 2 Euceratosa). All of these, with two exceptions, 

 were new to the Irish area, and six were new to science. Twenty-three 

 of the entire number were growing on coral, while a small piece of 

 sandstone had 6 species growing on an area of about 75 sq. mm. 



J. A. T. 



Protozoa. 



Intestinal Protozoa from Lizards. — C. M. Wenyon {Parasitology, 

 1920, 12, 350-65, 2 pis., 2 figs.). A full description of a flagellate of 

 the Leptomonad type from the rectum and cloaca of the chameleon. 



