474: SUMMAKY OF CURRENT RESEARCHES RELATING TO 



normally about 450 microns in length. Individuals have been reported 

 measuring 800 microns ! " 



A fifth environmental type consists of ditches and pools choked with 

 heavy luxuriant masses of algae, and exposed to tlie sun during the entire 

 day. The predominant forms are -.—Cercomonm terma, Ghlamydomonas, 

 Diffliigia globulosa, Eugleiia viridis, Monas Jiuida, M. irregularis. Peri- 

 dinium cinctum, Synura uvella, and Trepomonas agilis. 



Blood-parasites of African Apes and Monkeys.* — Eduard Reichenow 

 deals with Laverania malarise (the cause of paludism) in the chimpanzee ? 

 with trypanosomes (T. lewisi primatum) from Cercopithecus cepJws, 

 Ferodicticus, and the chimpanzee ; with TroglodytelJa gorilJse sp. n., a 

 remarkable Ophryoscolecid Inf usorian from the colon of the gorilla ; and 

 with a new sub-species of T. ahrassarti, from the chimpanzee. 



Cysts of EntamoBba dysenterise.j — C. Mathis and L. Mercier de- 

 scribe this stage, which is marked by the presence of four nuclei and 

 often by a rod-like chromidium. Full information is given as to dimen- 

 sions, and it is shown that there are macrocysts and microcysts with 

 precisely similar histories. The development of the four nuclei from one 

 is described. There is no emission of chromatin from the nucleus, as 

 Hartmann described. If there is any sex-phenomenon it probably occurs 

 after the ingestion of the cysts and the liberation of their contents. It 

 is possible that the microcysts and macrocysts are gametocytes giving 

 origin to gamete-amoebae of two sexes. 



Division of Entamceba dysenterise.^— C. Mathis and L. Mercier 

 find that this parasite multiplies solely by simple division. There is no 

 multiple division or schizogony, as has been asserted. There is a mitosis, 

 effected within the nuclear membrane (a " mesomitosis " in Chatton's 

 terminology). There must be a very rapid division of the cytoplasm, 

 but it was not observed. 



Entamoeba from Dipteron Larva.§ — D. Keilin describes a new 

 Entamoeba {E. mesniU, sp, n.) which lives as a parasite in the intestine 

 of the larva of Trichocera hiemalis and T. annulata. This entamoeba 

 resembles other known forms in its parasitic mode of life, in its large 

 pseudopods and in the absence of contractile vacuoles. It differs from 

 them in the presence of several nuclei throughout the whole vegetative 

 phase, and of adhesive protoplasm on its posterior margin. The investi- 

 gator recalls the fact that many authors have refused to recognize 

 plurinuclear vegetative forms leading on to multiple schizogony, as 

 described by Councilman and Lafleur for E. dysenterise, and have in- 

 terpreted them either as forms leading towards the sporogonic cycle, or 

 as degenerate. Doubt has recently been expressed by James as to the 



* Boll. Soc. Espau. Hist. Nat., xvii. (1917) pp. 312-34 (2 pis. and 1 fig.), 

 + C.R. Soc. Biol. Paris, ixxix. (1916) pp. 980-2. 

 t C.R. Soc. Biol. Paris, Ixxix. (1916) pp. 982-4. 

 § C.R. Soc. Biol. Paris, Ixxx. (1917) pp. 133-6. 



