176 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Coelentera. 



Fat in Sea-anemones.* — W. Arndt finds, in Heliactis bellis, that 

 the endoderin-cells, some of the ectoderm-cells, and the zooxanthellae 

 include a lipoid substance. It is absent from the mesoglcea. Fresh 

 specimens show it more abundantly than those that have been kept in 

 captivity for a considerable time. The fat probably comes from the 

 food, not from the symbiotic alga?. It may be said that H. bellis 

 exhibits Steatosis physiologica. 



Structure of Sea-anemones. f — Chas. L. Walton and Olwen M. Eees 

 communicate some details as to the muscle characters and the like in 

 their discussion of some rare and interesting sea-anemones from Plymouth 

 — Edwardsia tlmida Quatrefages, E. claparedi Panceri, Hakampa chry- 

 santhellum Peach, B. arenaria Haddon, and Eloactis mazeli Jourdan. 

 Of the last a detailed account is given by Rees.J It is an elongated 

 anemone, with twenty highly-specialized tentacles (to which the nemato- 

 cysts are restricted), ten pairs of perfect and fully-developed mesenteries, 

 and a deep well-defined siphonoglyph. It is probably intermediate 

 between Halcurias and Peachia. 



Axis of Alcyonarians.§ — K. Kinoshita corroborates the view of 

 Koch that the axis of Gorgonacea arises as a secretion product of an 

 axis-epithelium, and not in the interior of the ccenenchyma as Kolliker 

 concluded. The polyps are all of the same order, and the Gorgonid 

 type is not derivable from a Telestid type. The Gorgonids should 

 rather be derived from the stock of the Stolonifera. In Scleraxonia 

 three main types may be recognized — Briareum, Melitodes, and Subero- 

 gorgia, and these may be derived from a Briareum-Paragorgia stock in 

 which there has been a thickening of the ccenenchyma in the direction 

 of the main axis. Some valuable figures of the internal structure of 

 the different types are given. 



Incubation in Antarctic Alcyonarians || — Ch. Gravier describes 

 in Mopsea gracilis Gravier a kind of zooid, apparently without tentacles, 

 containing one large egg. There is marked dimorphism. In Mopsea 

 elongata Roule there are nodosities on some of the branches, each of 

 which lodges a large egg or occasionally two eggs. In Rhopalonella 

 pendulina Roule many of the branches show swellings containing yellow 

 bodies, each of which is an ovum surrounded by vitelline cells. Gravier 

 recalls the incubation among Antarctic Actinians, Echinoderms, and 

 Polychsets. It appears that special protection has been evolved for a 

 relatively small number of large ova. 



* Zool. Jahrb., xxxiv. (1913) pp. 27-42 (1 pi .). 



t Journ. Marine Biol. Assoc, x. (1913) pp. 60-9 (2 figs.). 



% Journ. Marine Biol. Assoc, x. (1913) pp. 70-80 (4 figs). 



§ Journ. Coll. Sci. Tokyo, xxxii. (1913) pp. 1-50(13 figs.). 



|| Comptes Rendus, clvii. (1913) pp. 1470-3. 



