ZOOLOGY AND BOTANY, MICROSCOPY, ETC. I , 5 



equatorial plate is formed chiefly at the expense of the peripheral 

 chromatin, to which is added a variable quantity of chromatin coming 

 from the karyosome. 



Depression and Apogamy in Amoeba diploidea.* — Rh. Erdmann 

 has studied the degenerative nuclear changes and other signs of 

 " depression " in this Amoeba when the culture was kept at a tempera- 

 ture higher than the normal (25°-37° C). The most interesting feature 

 was the entire cessation of any sexual process. A facultative apogamy 

 obtains, and the culture cannot be kept alive except by artificial aids. 

 The sexual process which normally occurs has for part of its utility the 

 counteracting of depressions and disturbances of the cell-functions. 



Rhizopods from Lake District.! — James M. Brown has identified 

 about fifty species from the English Lake District. Many are common 

 forms ; others, again, are less well known, while a few do not seem to 

 have been recorded from this country. Among these Paulinella chromato- 

 phora Lauterborn, is of interest, having been found in only a few places 

 on the Continent and in North America, and only as a single specimen 

 from Loch Ness. 



Notes on Marine Heliozoon.f — Maurice Caullery has found at 

 Banyuls on the fronds of a seaweed {Peyssonelia) an interesting Helio- 

 zoon, Gymnosphssra alb Ida Sassaki. It was previously found in the 

 aquarium of the Zoological Institute at Munich, and probably came from 

 Rovigno. It is about half a millimetre in diameter and easily seen with 

 the naked eye. The nuclei are variable in number, up to twenty or 

 thirty. The pseudopodia sometimes anastomose. Another new point is 

 that individuals occur well-armoured with borrowed spicules of sponge 

 and Holothurian. 



Vegetative and Reproductive Processes in Thalassicolla.§ — Th. 

 Moroff describes what goes on in this Radiolarian during the vegetative 

 and reproductive phases, with particular reference to the behaviour of 

 the unusually large nucleus (O'S-0'4 mm. in diameter). He describes 

 in detail, with very striking illustrations, the formation of isospores and 

 anisospores, and discusses such points as the significance of nucleoli 

 which are interpreted as forms of chromidia. 



Hsemocystidium of the Gecko.|| — C. C. Dobell has investigated 

 Hsemocijstidium simondi Castellani et Willey, a blood parasite of a Ceylon 

 gecko {Hemidactylus leschenauUii). He describes the schizogony and 

 the formation of the gametocytes. The genus Hsemocystidium is related 

 to the malaria parasite Plasmodium, but the intracorpuscular phases are 

 not amoeboid ; the schizogony takes the form of a simple bipartition, 

 rarely a division into four ; and the occurrence, so far as is known, is 

 confined to cold-blooded animals. 



* Festschrift Richard Hertwig, i. (1910) pp. 325-48 (2 pis. and 5 figs.). 



t Journ. Linn. Soc. (Zool.) xxx. (1910) pp. 360-8 (1 pi.). 



J Bull. Soc. Zool.,xxxvi. (1911) pp. 3-7. 



§ Festschrift Richard Hertwig, i. (1910) pp. 73-122 (65 figs.). 



|| Tom. cit., pp. 123-32 (1 pi.). 



