ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 165' 



site on various species of Chlamydomonas. The zoospores at the time 

 of their liberation are colourless, and possess a posterior flagellum as- 

 long as the body. The nucleus is large and the nucleolus appears to 

 be absent. These zoospores attach themselves to specimens of Chlamy- 

 domonas, often larger than themselves, and rapidly absorb the cell-con- 

 tents, becoming green in the process owing to the absorption of the 

 chlorophyll of the host, and also greatly distended. A very remarkable 

 circumstance is that Colpodella, after the ingestion of the cell-contents 

 of the victim, may contain more starch than the latter did in life. The 

 author suggests that the ingested chlorophyll preserves its active pro- 

 perties for some time after being absorbed. After a longer or shorten 

 period the zoospores give rise to sporangia, within which new zoospores 

 are formed. As to the position of Colpodella, the author is disposed to 

 regard it as a highly differentiated member of the Flagellata. 



Apparent Commensalism of Conochilus and Vorticellids.* — H. A. 

 Doty describes swimming colonies of Conochilus in the jelly of which 

 Vorticellids (Vorticella ?) were imbedded. The stalks were abortive, 

 tapering to invisibility at a distance from the body equal to about twice 

 its length. The half of the stalk next the body of the Vorticellid was 

 contractile, but the inner half was very slender and lost itself in the 

 jelly. No sheath was discernible. To the Vorticellids the advantage 

 of protection and economy in locomotion seemed obvious, but it is not 

 evident that Conochilus derives any benefit. If so, the Vorticellid is 

 rather epizoic than commensal. There is an unfortunate vagueness in 

 the communication. 



New Species of Gonyostomum.f — Herr L. Iwanoff describes G. 

 latum sp. n., a new representative of this rare genus, hitherto known 

 only from G. semen (Ehrenberg's Monas semen). 



Coccidium fuscum.| — Dr. Valentin Voirin has studied the disease 

 in pigs known as Schrotausschlag, which is characterised by the 

 formation of shot-like granules in the skin. The disease, as was first 

 shown by Olt, is due to the occurrence within the sweat-glands of 

 Coccidium fuscum. In their earlier stages of development the coccidia 

 live in the gland-epithelium, but later stages occur free in the lumen 

 of the gland, as well as in the skin-cysts which are outgrowths of the 

 infected glands. The intracellular parasites are naked and show 

 amoeboid movements, while those which occur free are encysted. Of 

 these encysted forms two distinct varieties occur: — (1) oval cells with 

 thick shells which give rise to coated resting spores ; and (2) rounded 

 cells with a thin investment which give rise either to eight macro- 

 gametes or to 30-40 microgametes. Though some stages of the de- 

 velopment are obscure, the author believes that a comparison with the 

 results of others justifies the following statement of the life-history. 

 The young develope within the epithelial cells, become adult, and, leav- 

 ing these cells, multiply endogenously to form sickle-shaped embryos 

 (macrogametes), which can directly infect new epithelial cells of the 

 same gland, or, emerging by the gland-pore, may even attack neighbour- 



* Journ. Applied Microscopy, iii. pp. 989-90 (2 figs.). 



r Bull. Soc. Imp. Nat. Moscou, 1899, No. 4 (published 1900), pp. 417-9 (1 pi.). 



X Zool. Jahrb., xiv. (1900) pp. 61-106 (1 pi.). 



