ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
645 
An observation made by Aime Schneider on the condensation of a cloud 
of fine granulations within the nucleus of Gregarines ( Actinocephalus , &c.) 
suggested to the author that the intranuclear bodies of Foraminifera and 
other Protozoa arise from the coalescence of substances at first fluid, then 
viscid, and finally firm. He works out this idea in detail, considering 
the various physical conditions in the process of coalescence. The 
bodies in question are not organized structures, certainly not cell-organs, 
but most likely aggregations of reserve material. 
Destruction of Bacteria by Infusoria.* — Mr. D. Harvey Attfield 
brings forward some evidence that the so-called self-purification of 
impure water may be due to Infusoria. Into two sterilized flasks 
there were introduced 500 ccm. of well-water which was estimated to 
contain 10,000 bacteria per ccm. To one flask there was added 10 ccm. 
of river Isar water, which swarmed with Infusoria (chiefly Paramsecium 
aurelia and P. caudatum). It was found, by plate cultivations, that in 
water swarming with Infusoria the bacteria had decreased to less 
than one-fifth their original number in six days, while in water con- 
taining few or no Infusoria the decrease of bacteria in six days was only 
one-half of the original number. Other experiments led to similar 
results. 
Coccidia of Birds. ] — M. A. Labbe finds that the Coccidia found in 
the intestine and caeca of Birds belong to two groups. Some belong to 
the genus Coccidium and are very near the C. perforans of the Babbit. 
In Passerines one frequently finds a spherical Coccidium with two 
equal sporoblasts, each enclosing four sporozoites ; for this form the 
author has made the genus Diplospora, which is intermediate between 
Cyclospora and Isospora. In addition to a chronic infection of Coccidia, 
Birds may suffer from an acute attack which may be fatal. The author’s 
observations suggest to him the question whether there may not be a 
dimorphism in development and an endogenous proliferation of 
sporozoites. 
Organization of Choanoflagellata.J — Herr B. H. Franze calls 
attention to some points in the organization of the Choanoflagellata. 
He finds that Biitschli’s account of the ingestion of food in Codosiga 
botrytis is hardly correct. The collar is connected with one of the 
contractile vacuoles by a fine curved line. This line corresponds to the 
boundary of a delieate plasmatic membrane, which, at times, leads to 
the vacuole, and it is by this membrane that the food-bodies pass to the 
digestive vacuole. It was the middle part of this membrane that 
Biitschli took for the mouth vacuole. The collar is not a circular ap- 
pendage closed on all sides, but a cornet-shaped membrane which takes 
part in the ingestion of food. The contractions of the vacuole are not 
pulsations but swallowing movements. 
The other, true, contractile vacuole pulsates at pretty regular inter- 
vals of about thirty seconds. It is remade by the appearance of one, 
then two, then three, very small vacuoles which suddenly unite ; at the 
same time there become apparent two fine longitudinal canals which 
* Brit. Med. Journal, 1893, i. pp. 1262 and 3. 
t Comptes Rendus, cxvi. (1893) pp. 1300-3. 
X Zool. Anzeig., xvi. (1893) pp. 44-G (2 figs ). 
2 y 2 
