812 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The stem and branches, which occasionally anastomose, and form 

 a network, taking on tho shapo of tho spongo in nearly every detail, 

 are formed of ordinary vegetablo cells, remarkable for their very 

 thick walls. Spicules, liko those of the sponge, were found on burning 

 tho alga ; but no traco of the horny skeleton. Tho author regards 

 this alga as ono of the Floridea) : " The alga is a parasitic species 

 growing in the sponge, extending throughout the whole body of it. 

 The sponge is thereby resorbed by the alga, the soft parts and fibres 

 disappear, whilst tho siliceous spicules are left adhering to the outer 

 side of tho branches of the alga." This alga forms a true pseudo- 

 morph ; and the author does not think it comparable to other more 

 simple alga parasites in sponges. 



Sponges from South Australia.* — Mr. H. J. Carter continues his 

 description f of the sponges obtained from the neighbourhood of Port 

 Philip Heads. 



In this communication he prefaces his account of the calcareous 

 sponges by a reference to Hiickel's classification, and to Polejaeff's 

 rearrangement of this system, and calls attention to the parts to be 

 noted in a description of a sponge, e. g. general form, colour, and 

 structure of the surface, and explains the terms which he uses in his 

 description of the specimens. The author prefers " vent " for the 

 aperture usually known as the " osculuni " ; the " cloaca " is the cavity 

 into which this opens, and so on. The various terms used in 

 describing acerate, tri-radiate, and quadriradiate spicules, such as 

 " lanciform," " sagittal," " inarticulated," &c, are explained. 



Clathrina cavata is a representative of a common British species, 

 but differs from it in that the cylindrical prolongations on the surface 

 comunmicate only with the dilated parts of the interspaces ; in C. 

 laminoclathrata the tabulated staple thread so common in the genus 

 is replaced by a flat-soled staple ; C. primordialis presents a still 

 further approximation of the parenchymatous structure, which inter- 

 venes between the contorted tubulation, to the arrangement which 

 obtains in the Leucones and Teichonellida3. The largest and most 

 abundant species is C.ventricosa ; it was found to be abundantly filled 

 with large ova. In all eight new species of Clathrina are described. 



In a subsequent paper J he continues his account of the calcareous 

 sponges, and describes 19 species; Hypograntia and Heteropia are 

 new types ; in the former there are large holes of intercommunication 

 between the chambers, and in the latter the wall consists merely of 

 sarcode supported on large sagittiform triradial spicules. 



Protozoa. 



Conjugation of Ciliated Infusoria.§ — M. E. Maupas has studied 

 completely the conjugation of Colpodium colpoda, Paramecium aurelia, 

 and Euplotes patella var. eurystomus. He believes he is able to 



* Ann. and Mag. Nat. Hist., xvii. (1886) pp. 431-41, 502-16. 



t See this Journal, ante, p. 258. 



\ Ann. and Mag. Nat. Hist., xviii. (1886) pp. 34-55. 



§ Coniptes Iieudus, cii. (1886) pp. 1569-72. 



