ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 519 



prolongation directed backwards, or better at the dorsal rostrum 

 (which is itself prolonged) where it often forms a long point. It 

 also presents, besides the line devoid of green colouring matter, the 

 existence of which on the left face the author has already recorded, 

 another, colourless, tolerably broad, longitudinal line through the 

 whole length of the right face. Finally the starch-grains of the deep 

 mamillated layer are rarer and very thin ; but extending over 

 almost every part of their body are seen some irregular more 

 refringent corpuscles resembling concretions, which are perhaps also 

 formed of starch, although they do not turn blue under the influence 

 of iodine. 



In an infusion that was in an advanced state of decomposition the 

 author has met with Chilomonas parammcium Ehrb. in a sort of 

 palmelloid state ; a number of individuals of this species being 

 united in a common transparent gelatinous mass, having a great 

 resemblance to a Zooglea. Cienkowski has observed an analogous 

 phenomenon in Cryptomonas polymorpha, and was confident that it was 

 a mode of reproduction. The author has never observed this 

 phenomenon except in cultures which were more or less putrefied 

 and placed in unfavourable conditions with regard to light; these 

 organisms are always isolated and very active in clear water well 

 exposed to the light. Astasia costata has a muscular, subcuticular 

 layer with spiral fibrillae analogous to those in the Euglenoz. The 

 contractile vesicle of Phacus pleuronectes Duj. has distinctive vacuolar 

 walls resembling those of the analogous organ in Cryptomonas. The 

 terminal flagellum of Nonas vinosa Ehrbg. that Cohn considers to be 

 merely the mobile spore of Clathrocystis roseopersicina (a chromogenous 

 bacterium), displays a transverse striation when it has been submitted 

 to the action of reagents that colour strongly. 



Cell-parasite of Frog's Blood and Spleen (Drepanidium 

 ranarum).* — In 1880 we referred f to a discovery made by Dr. J. 

 Gaule of certain Wurmchen or " vermicles " in frog's blood, which 

 he considered to be simply protoplasmic portions of the corpuscles 

 separated for a short independent life, and not parasitic organisms. 

 Prof. Eay Lankester now points out that these are, in fact, the minute, 

 sausage-like parasites, discovered by him in 1871 (for which he 

 proposes the name of Drepanidium ranarum), and that they are 

 clearly parasitic organisms, probably the young stage of a sporozoon 

 allied to Sarcocystis or to Coccidium. 



Some of the chief observations of Dr. Gaule are, in fact, directly 

 favourable to the view that the Wurmchen are independent parasitic 

 organisms, for (1) they exhibit active movements under circumstances 

 usually favourable to the movements of the Protozoa and Protophyta ; 

 (2) they occur within the cells of the organism in which they are 

 found as well as in its fluids ; (3) they are present in some frogs and 

 not in others living under approximately the same conditions ; (4) they 

 vary in abundance in the same frog, examined at different times ; 



* Quart. Journ. Micr. Sci., xxii. (1882) pp. 53-65 (5 figs.), 

 t This Journal, iii. (1880) p. 232. 



