396 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



changed the mode of nutrition, or it may be that the numerous and con- 

 spicuous chloroplastids makes the detection of the " glands " difficult. 



It will be seen that Miss Greenwood's description does not tally with 

 views generally held ; she thinks that lack of continuity in observation 

 has led to the interpretation of what is really a phase of structure as a 

 permanent histological condition. 



Porifera. 



Chromatology of British Sponges.* — Dr. C. A. MacMunn has found 

 chlorophyll in ten out of twelve species of marine sponges ; this may be 

 shown to be of purely animal origin by various tests. It is very probable 

 that it* is of use in the constructive metabolism of animals by removing 

 waste carbonic acid, and then by the influence of light building up from 

 carbonic acid and water some substances, such as starch, glycogen, sugar, 

 or fat, which are of direct service to the animal. It does not seem likely 

 that the chlorophyll has a respiratory function, for the union between it 

 and oxygen cannot be loose, as it is in the case of hasmoglobin, and a 

 histiohaematin which is of respiratory use may coexist with chlorophyll 

 in Sponges. 



Notes on Sponges.f — Dr. E, Topsent first deals with Dendoryx 

 Hyndmanni and the other species of that genus; one new form, 

 D. luciensis, is described. He gives reasons for including in this genus a 

 number of species which were placed by Bowerbank with Halichondria, 

 Isodidyon, and Hymenacidon, as well as various species described by 

 other authors. In a second essay he gives an account of the larval stage 

 of Bysidea fragilis, which is shown by its embryology, as much as by its 

 anatomy, to be a Spongelia. 



Sponges from the Gulf of Manaar.| — Mr. A. Dendy gives an 

 account of a second collection of sponges made by Mr. Thurston ; of the 

 twenty-four determinable species fourteen are new to science, and two are 

 represented by new varieties ; the great majority are Monaxonids. The 

 characters of Axinella tuhulata seem to have been misunderstood by the 

 late Dr. Bowerbank; its peculiarities are due to the presence of a com- 

 mensal tubicolous oligochsetous annelid ; it is not yet known whether 

 either the worm or the sponge ever live separately ; Mr. Dendy points 

 out that Canon Norman's new generic name Aulospongus for this species 

 is unnecessary. The genus Auletta has not yet been found except in the 

 Atlant'c and Arctic oceans ; the species discovered by Mr. Thurston is 

 called A. aurantiaca. Mr. Dendy, from his own observations and from 

 that of Mr. Bracebridge Wilson, is inclined to believe that the colours of 

 living sponges will be found to be of great service in distinguishing 

 species ; the sponges here reported on seem to have had great brilliance 

 and variety of natural colouring. 



New British Species of Microciona.§— Messrs. H. J. Carter and E. 

 Hope give an account of Microciona spinascus sp. n. from Hastings. Mr. 

 Carter formerly referred it to M. armata Bowerbank on the supposition 

 that the spiniferous character of the ends of the tricurvate spicules had 

 been overlooked by Bowerbank, but he is now convinced that he was 

 mistaken in that view. 



* Joum. of Phvsiol., ix. (1S8S) pp. 1-25 (1 pi.), 

 t Arch. Zool. Bxpe'r. et Gen., vi. (1888 j pp. xxxiii.-xliij. 

 X Ann. and Mag. Nat. Hist., iii. (1889) pp. 73-99 (3 pis.). 

 § T. c, pp. 99-106 (1 pi.). 



