446 SUMMARY OF CURKKNT RESEARCHES RELATING TO 



Dimorphism in English Species of Nummulites.* — J. J. Lister has 

 examined the characters of Nummulites Ueviyata Brag., N. variolnria 

 Lam., and N. eleyans Sow., with respect to dimorphism. His results 

 are in complete accord with the conclusion that the species of Nummulites 

 are dimorphic. We have, however, to recognise that while in many 

 species of the genus the microspheric form attains a much larger size 

 than the megalospheric, in others the two forms attain the same size— a 

 condition which is indeed the rule in the great majority of the 

 Forarninifera. 



Notes on Infusorians.f — W. D. Henderson communicates a number 

 of brief notes on a large number of Infusorians collected round Freiburg. 

 Over eighty species were collected in a short time. Most of the notes 

 corroborate previous descriptions, but a few observed differences of 

 interest are recorded, e.g. the apparent absence of a micronucleus in 

 Spirostomum am biguum. 



Flagellata in Blood of Fresh-water Fishes. J — Keysselitz reports 

 on a large number of cases in which he has found in the blood and 

 lymph of fresh-water fishes representatives of the genera Trypanoplasma 

 and Trypanosoma. 



Movements of 6regarines.§ — 'Howard Crawley discusses the various 

 movements of Gregarines, and lays all emphasis on the " myocyte," the 

 layer of fibrils which encircles the animal in a slightly spiral direction, 

 with circular fibres united by longitudinal and diagonal connectives, the 

 whole system forming a net. After discussing the various interpretations 

 and stating his observations, he comes to the conclusion that all the 

 motor phenomena which the Polycystidea display may be directly credited 

 to contractions of the myocyte, with the possible exception of the 

 amoeboid movements of certain species, and the rotation. 



Metameric Cytoplasm in 6regarine.|| — L. Leger describes from the 

 intestine of the larva of Ceratopogon solstitialis Winn., from marshes 

 near Cavaliere, a remarkable new cellular type, which he names Tcenia- 

 cystis mira g. et sp. n. It is a Gregarine of long, worm-like shape, 

 whose cytoplasm is divided into numerous compartments by transverse 

 septa ; it resembles a small Cestode. The number of segments increases 

 with the size of the animal, which reaches 300 p. As many as twenty- 

 nine segments have been observed. Anteriorly the shape undergoes 

 change of form, becoming beak-shaped : this is probably for adhesion. 

 A single spherical nucleus is present in the sixth or seventh segment. 

 The cell is covered by a thin cuticle, and there is no ectoplasmic layer. 



Anisogamy in Monocystis.1[ — L. Brasil finds that, contrary to the 

 general view, conjugation in Monocystis is anisogamous, although not to 

 the same degree as in Stylorhynchus and Pterocephalus. Isogamy, he 

 considers, is probably the exception rather than the rule in Monocystids. 



* Proc. Cambridge Fhil. Soc, xiii. (1905) pp. 1-2. 



t Zool. Anzei*;., xxix. (1905) 21 pp. and 6 figs. 



J SB. Ges. Natur. Freunde (Berlin, 1901) pp. 285-1)6. 



§ Proc. Acad. Nat. Sci. Philadelphia, 1905) pp. 89-99. 



|| Comptes Rendus, cxl. (1905) pp. 521-6. f Tom. cit., pp. 7^5-6. 



