600 SUMMARY OF CURRENT RESEARCHES RELATING TO 



three species, — Bathypnthes patula var. plenispina Brook, R. alternata 

 Brook, and B. bifida sp. n. In the new species, a slender basal piece 

 Tises vertically to a height of 15 mm., and then bifurcates into two long 

 branches which extend in opposite directions for about 16 cm. The 

 most remarkable feature in the polyps is the length (up to 3 mm.) of the 

 lateral tentacles. 



Porifera. 



Chilian Sponges.* — J. Thiele reports on the silicious and horny 

 sponges of Plate's collection, including 80 species many of which are 

 new. 



Protozoa. 



Genus Amoeba.! — E. Penard discusses the genus Amceba, which, in 

 spite of acknowledged difficulties, he maintains to be "autonomous" 

 and separable from the numerous pseud-amcebee which are familiar to 

 all naturalists. Too many young forms and mere phases have been 

 thrown into the " Pot aux amibes," but Penard does not despair of the 

 genus — " genre embrouille, veritable chaos peut-etre, mais chaos dont on 

 sortira quelque jour." 



Protozoa in Human Faeces 4 — A. Castellani describes Nyctotherus 

 africanus sp. n., in the fasces of a Baganda native affected with sleeping 

 sickness. The most interesting feature of the parasite is in the macro- 

 nucleus, which is very large, rounded in shape, and has, as Schaudinn 

 described in Nyctotherus faba, its chromatin collected in four large 

 masses at the periphery. In a case of chronic dysentery, Castellani 

 found Entamoeba undulans sp. n., an oval or roundish form without 

 flagella, with one pseudopodium at a time, and with a continuous rapid 

 undulatory movement from one extremity to the other, this being due 

 to the presence of an undulatory membrane. 



Radiolarian Skeleton .§ — V. Hacker points out that the mechanical 

 interpretation of the skeletal structure of Radiolarians requires to be 

 supplemented by a biological interpretation showing the functional im- 

 port of the various architectural arrangements. It is this latter mode of 

 interpretation which he has very convincingly worked out in the present 

 memoir. Thus, to take a particular case, he shows how the three-jointed 

 elastic system, illustrated by the radial spines of Auloscena verticillus, is 

 in its minutest details adapted to the function of supporting the sarcode- 

 membrane. The candelabra-like arrangement of the appendicular parts 

 is adapted to keep the strongly developed sarcode-membrane at a 

 uniform distance from the lattice-work of the shell, while in A.pelagka 

 the structure of the skeleton is adapted to the finger -like evaginations 

 and corresponding deep depressions of the soft body. In the same 

 genus we find different adaptations to the conditions of the deep cold 

 abysses, and to the planktonic conditions of the warm surface water. It 

 is suggested that the biological interpretation of the Radiolarian skeleton, 



* Zool. Jahrb. (1905) Supplement vi., Bd. 3, Heft 3, pp. 407-96 (7 pis.). 



t Rev, Suisse Zool., xiii. (1905) pp. 401-9. 



\ Centralbl. Bakt. Parasitenk., xxxviii. (1905) pp 66-9 (5 figs.). 



§ Jenaische Zeitschr. Naturwiss., xxxix. (1905) pp. 581-648 (28 figs.). 



