180 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Skeleton of Peridinids.* — C. A. Kofoid gives a detailed account of 

 the structure of Peridinium steini Jorgensen. He discusses the nomen- 

 clature and gives a table showing the synonyms. He also gives an 

 account of the skeleton in Podolampas eleyans. It consists of two apical, 

 one intercalary, six precingular, three postcingular, four antapical plates, 

 and a ventral area in which four divisions are recognisable : instead of 

 one apical, five precingular, three postcingular, and two antapicals and a 

 longitudinal furrow plate as heretofore stated. The missing girdle is 

 represented by a narrow band fused to the lower ends of the precingular 

 plates. On the surface of this band which is in the place along which 

 the transverse flagellum passes, is a very shallow furrow. The so-called 

 girdle (Schiitt) of Blepharocysta striata is in reality the band of three 

 postcingular plates. The "comb-like furrow" of Stein is a band of 

 peculiar alternating pores on the antapical plates. The pores are highly 

 differentiated and are distributed with reference to the movement of 

 fluids and plasma of the cell-body. The plates are united by oblique 

 sutures with overlapping edges and denticles intercalated between the 

 elements of the bands of striae. These striae represent differentiations in 

 the substance of the wall rather than surface ridges. 



Studies of Trypanosomes.f — N. H. Swellengrebel gives an account 

 of the structure and division of Trypanosoma gambiense and T. eguinum. 

 He deals, for instance, with the achromatin axial filament running through 

 the cell. It splits longitudinally in the division, and plays a role in 

 nuclear division like that of the nucleolo-centrosome in Euglena. It is 

 comparable to the axial rod in Trichomastix and Trichomonas. 



Howard Crawley $ describes Trypanosoma americanum sp. u., which 

 seems to be a common parasite in healthy American cattle. Its structural 

 peculiarity is that the trophonucleus and kinetonucleus lie very close 

 together. This peculiarity is shown by T. transvaliense, taken to be a 

 variety of T. theileri, and, as well as can be made out from his figures, by 

 the trypanosome found by Miyajima. If this last fact be so, then Miyajima 

 is in error in his conclusion that his flagellate is a phase of Piroplasma. 

 The fact that trypanosomes occur in cultures of blood from healthy 

 cattle is decidedly against the theory that they are stages in the life-history 

 of a Hasmosporidian. 



Cryptobia and Trypanoplasma.§ — Howard Crawley points out that 

 Leidy used the term Cryptobia in 1846 for organisms which would now 

 be referred to the genus Trypanoplasma Laveran and Mesnil. He after- 

 wards abandoned the name because of its resemblance to C'ryptobium, but 

 according to the tyrannical rules of priority it must stand and replace 

 Trypanoplasma. 



Piroplasma of Hedgehog. || — W. L. Yakimoff describes Piroplasma 

 niiiense sp. n. from the blood of the hedgehog. Its intermediate host is 

 the nymph of a tick, Dermatocentor reticulatus, the adult of which is the 

 bearer of a Piroplasma in horses. 



* Archiv Protistenk., xvi. (1909) pp. 25-61 (2 pis.). 



t Tijdschr. Nederland. Dierk. Ver., xi. (1909) pp. 80-98 (1 pi.). 



X Bureau Animal Industry, U.S. Dept. Agric, Bull. 119 (1909) pp. 21-31 (1 fig.). 



§"Tom. cit., pp. 16-19 (1 fig.). 



|l Centralbl. Bakt. Parasitenk., lii. (1909) pp. 472-7 (1 pi.). 



