470 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Cyanea, and a blue matter called hcEmocyanine found in tlie blood of 

 the Octopus, which, however, has no definite absorption bands.* 



Australian Distichopora.t — Though the title of this paper by 

 the Rev. J. E. Tenison- Woods is " On the Anatomy of Distichopora, 

 with a Monograi)h of the Genus," it is rather a descriptive list of the 

 Australian living Distichopora than a paper on their anatomy. As a 

 list, however, it is very useful to all studying the Hydrocorallinje, as 

 the work already done is well reviewed. The references are full, 

 ranging from those of Pallas, Blainville, Lamarck, Milne-Edwards, 

 Agassiz, &c., up to the more recent observations of Mr. Moseley, 

 whose classification is adopted. There appear to be eleven species 

 known to be living in the Australian seas. 



Observations on Hydroid Polyps.J — Dr. A. Weismann, in direct- 

 ing attention to the pulsation of the body of Hydroids, points out 

 that it is not correct to suppose, as is generally done, that the circu- 

 lation of the fluid in the body is altogether efiected by the flagella of 

 the endodermal cells ; at certain points the body-wall contracts 

 rhythmically. This was first seen in the gonophores of Goryne 

 pusilla, when the author was attempting to draw them. Closer 

 examination showed that the endodei'mal tube alternately enlarged 

 and contracted ; in the systole the cavity of the gonophore became 

 invisible and the walls of the endoderm came together. From what 

 the author has seen he concludes that there is a muscular layer 

 between the endoderm and the mass of genital products, and this 

 band becomes thicker during the systole. 



In Plumulariidse and Campanulariidae the author finds that the 

 musculature is not, as has been supposed, confined to the hydranths, 

 but that it extends over the whole trunk and all its branches ; every- 

 where there is a single layer of elongated, spindle-shaped muscular 

 fibres, lying above the supporting lamella. In Plumularia, at any 

 rate, it consists of independent nucleated cells, which at most points 

 form a regular simple layer around the endodermal tube ; its function 

 would appear to be to aid in the circulation of the blood. 



As to movements of the ectoderm, Dr. Weismann finds that the 

 processes by which the polyp is attached to its tube are during 

 life in nearly constant movement, which is slow and amoeboid, but 

 not passive, as is shown by the fact that new processes of attachment 

 may become developed, fine filaments of ectoderm gradually growing 

 larger and thicker. There is therefore a close analogy with the 

 pseudopodial processes by means of which some Khizopods are 

 attached to their shell. 



Formation of Ova in Eudendrium.§ — In a further note Dr. Weis- 

 mann points out that the diiferences between the account he now gives 

 and that which he gave on a previous occasion are due to the fact that 

 diflferent species were under observation. In E. racemosum Cav. the 

 egg-cells are formed in the ectoderm of the coenosarcal tube, and, at a 



* See this Journal, ii. (1879) p. 164. 



t Journ. R. Soc. N. S. Wales, xiii. (1879) pp. 49-63 (2 pis.)- 



X Zool. Anzcig., iv. (1881) pp. 61-4. § Loc. cit., pp. 111-14. 



