496 SUMMARY OF CUERENT RESEARCHES RELATING TO 



distinctly seen under a very low magnification, and under high powers 

 the chromosomes (about fifty) can be counted. The chromosomes are 

 small masses of chromatin about 1 /x in diameter ; their outline is 

 approximately spherical but somewhat indistinct. 



Danish Plankton Protozoa.* — Carl Hansen-Ostenfeld gives an 

 account of the Protophytes and Protozoa of the Danish plankton. The 

 Protozoa include Flagellata like Dino'bryoii and Phseocystis^ Silico- 

 flagellata like Disteplianus^ and Peridiniales like Peridinium and 

 Geratiuyn. Numerous species are dealt with. 



Ciliata in Gut of Enchytrsaus.f — H. H. Stirrup reports the abundant 

 occurrence of Mesnihlla fastigiata in the gut of Enchytrseus jiellucidus. 

 Its average length is • 3-0 ' 4 mm. ; it is an elongated cylinder with 

 a curious swelling at the anterior end on one side ; the most charac- 

 teristic feature is a strong chitinous-like spicule running from one end 

 through the cell, and ending at about two-thirds the length in a fine 

 curled thread almost like the lash of a whip ; the macronucleus extends 

 the whole length of the cell ; no micronucleus was to be found. Three 

 other Giliata, which may be new, were found in the same situation. 



Intestinal Trypanoplasmas of Fishes. J — C. H. Martin discusses 

 Trypanoplasma congr% Heteromita dahlii ( = Trypanoplasma ventriculi)^ 

 and Try'pcmo2olasmoides intestinalis ( = Triypanoiolasma intestinalis and 

 CryptoUa intestinalis). He describes some division-stages of Trypano- 

 jjlasma cyprini in the crop of the leech. It may be that the new 

 flagella arise by splitting, but this is still doubtful. One blepharoplast 

 after division travels backwards as the kinetonucleus elongates. The 

 elongated kinetonucleus then divides by means of a simple transverse 

 constriction. The division of the trophonucleus is precisely similar to 

 that in T. congri. 



The confusion of the nomenclature of bimastigate Flagellates depends 

 largely on two factors — (1) the discovery of a free-living bimastigate 

 form with a kinetonucleus {ProwazeTcia), and the consequent doubt as to 

 how many of the original species of the genus Bodo may not turn out to 

 l)e Prowazekia ; and (2) the recent attempt made by certain authors, on 

 the assumption that the parasite in the receptaculum seminis of snails 

 is identical with the true Tryplanoplasmas, to place the intestinal 

 Trypanoplasmas in the genus Gytobia. The author also discusses the 

 view that the kinetonucleus is a true nucleus comparable to the tropho- 

 nucleus. 



Nuclei of Flagellates.§ — C. Gineste has studied the nuclear appa- 

 ratus in Bodo and related forms. In Bodo at its " Rhizomastix " stage, 

 and in young Trichomonads, the nucleus is simple as in an amoeba. 

 Later on the karyosome is extruded from the nucleus, and it probably 

 represents the micronucleus of Ciliata. The semilunar body described 

 as chromidial is probably the macronucleus of Ciliata. 



* Mem. Acad, Roy. Sci. Danemark, ix. (1913) pp. 117-413 (9 figs, and 75 tables). 



t Proc. Zool. Soc, 1913, pp. 316-17 (4 figs.). 



X Quart. Journ. Micr. Sci., lix. (1913) pp. 175-95 (2 pis. and 2 figs.). 



§ C.R. Soc. Biol. Paris, Ixxiv. (1913) pp. 405-8 (13 figs.). 



