cu 



88 SUMMAEY OF CUERENT EESEARCHES RELATING TO 



the complex skeletHJ architecture. The elements remain separate as 

 spicules in most Alcyonarians, but are united to forma compact skeleton 

 in others, and in all Madreporarians. " From this point of view, a 

 separate calcareous piece of an Alcyonarian might be regarded as a 

 diminutive corallum, and the corallum of a Madreporarian as a massive 

 spicuV, and finally, the formation of the Antliozoan skeleton would be 

 essentially similar to the formation of membrane bore in Vertebrates." 



J. A. T. 



Reactions of Astrseid Corals. — G. Matthai {Proc. Cambridge 

 Fliil. Soc, 11)18, 19, 164-6). Observations were made on species of 

 Mmandrina, Isophyllia, Favia and other genera. Ciliary movement 

 passes the food-particle into the nearest oral aperture. The mouth 

 dilates and the lip is directed towards the particle. The peristomial 

 cavity is narrowed and deepened, which helps to roll the food-particle 

 into the oral opening. There is an expansion of the tentacles of the 

 affected oral disc and of adjacent oral discs. There is an eversion of 

 the stomodajum and consequent exposure of the coelenteric cavity and 

 mesenterial coils. Then there is a restoration of the original condition. 



A tentacle touched with a fine glass needle is withdrawn in a 

 manner resembling pseudopodial movement. The movement spreads to 

 neighbouring polyps. The amoeboid appearance of t'ne movements is in 

 conformity with the author's view that there are no muscular or nervous 

 elements. The so-called muscular fibres at the base of ectoderm and 

 endoderm are specialized connective tissue fibres which are without 

 nuclei and form part of the mesogloea. J. A. T. 



Locomotion and Reactions of Charybdea. — Naohide Yatsu 

 {Journ. Coll. Sri. Univ. Tokyo, 1917, 40, Art. y, 1-12, 5 figs.). In the 

 Cubomedusan Charyhdea ruMonii the locomotor activity is not affected 

 V)y transference from diffused light to direct sunlight. Whatever be 

 the position of the medusa, the concretion is always at the lowermost 

 end of the rhopalium. Its extraction does not affect swimming. Medusse 

 deprived of all their rhopaUa usually cease to pulsate. In rare cases 

 they may exhibit weak pulsations, or even swim for a short distance. 

 The pulsation centre is located in the region of the rhopalium between 

 the eye part and the stalk. In the upper third of the bell and in the 

 region near the velarium the nerve plexus is probably lacking. Nerve 

 stimuli are not transmitted in those regions. Fatigue comes to the 

 pedalial muscles after fourteen to sixteen contractions as tested by the 

 rhopalium-pedalium reflex. The mouth margin is spread out if the 

 lower region of the subumbrella near the velarium is stroked. The 

 phacellse of this species are nine to ten in each inter-radial corner of 

 the ga-tial cavity, and are arranged at irregular intervals. Each is 

 composed of a very elastic stalk and a terminal tuft. J. A. T. 



Porifera. 



Larvae of Grantia compressa. — Olga M. Jorgensen {Report Dove 

 Marine Laboratory, Cullercoats, lliis. New Series, 7, 60-1, 9 figs.). 

 Actively swimming Amphiblastulae were collected by centrifuging from 



