ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 1011 



ments tliis abstract by tlie criticism of all points on which his own work 

 has led him to take a different view. Eothert's work was principally- 

 conducted on three forms of Saprolegnia belonging to the ferax group ; 

 and he has shown that these species are far more favourable than 

 Uictyuchus or AcMya. 



Chytridium elegans, n. sp., a Parasite of the Rotatoria.* — 

 Prof. E. Perroncito found that Philodina roseola Ehrenberg, the charac- 

 teristics of which are " Philodina roseola aut carnea, Itevis, ocellis 

 ovatis, pedis corniculis " was very common in the hot-springs of 

 Viuadio and Valdieri. These Eotatoria often die from disease produced 

 by vegetable parasites, of which the author has observed two instances. 

 One of these is characterized by the slowing down of the movement of 

 the rotifer, the body of which contracts to form a spherical mass. With 

 a magnification of 350-500 there can be observed in the body of the 

 animal cell elements with thick nucleus and sharply-defined nucleoli. 

 These cells are spherical, oval, or pyriform with well-defined outline and 

 with a diameter of 20-30 fx. 



With these cells the cuticula of the animal becomes completely filled, 

 and they are the cause of gradual death. The skin of the rotifer is finally 

 perforated by processes of the parasite. These processes are tubular 

 masses of protoplasm, and finally give exit to zoospores. When treated 

 with iodine water, the parasite turns yellow, and if sulphuric acid be 

 added, the nuclei of the cells become a deep red-violet. The spores 

 which at maturity form the contents of the parasitic cells are 2 /x, 

 rarely 3-4 /x broad, and reflect a pale yellow light. When quite ripe 

 the spores are reddish, oval, and mobile. In one cell there may be 30-50 

 or more 4-5 fi long, 2-3 /x broad, and each of them is provided with two 

 long delicate flagella. When free their movements are very lively. 



In form, structure, and development, this parasite shows great re- 

 semblance to some Chytridinete, their zoospores are identical, and they 

 have the same kind of development. The filamentous processes are, 

 however, simple, while in the best known forms of Chytridineaa they are 

 complex. This characteristic the author thinks is insufficient to make a 

 new genus, and he therefore calls his parasite Chytridium elegans n. sp. 



New Chytridium.f — Under the name Chytridium luxurians Herr A. 

 Tomaschek describes a new species distinguished by its rapid growth and 

 the great abundance of the zoosporangia. It made its appearance in the 

 method of pollen-grain cultivation of the lower fungi described by ZojDf 

 (for the proposal of which method Tomaschek claims priority), modified 

 in the following way. The pollen of conifers is scattered over several 

 layers of filter-paper and laid on an ordinary flower-pot filled with sand, 

 which is placed in a vessel of water and covered by a bell-glass. On the 

 pollen-grains are rapidly developed a number of forms belonging to the 

 lower fungi. 



Parasites of the Higher Fungi. I — M. J. Costantin describes and 

 discusses the correct position of several fungus-parasites found on Aga- 

 ricini and Pezizse : — 1. Asterothecium strigosum Wall., found on Peziza 

 hemispheerica, appears to be quite distinct from A. Pezizse Cord. 



* Centralbl. f. Bakteriol. u. Parasitenk., iv. (1888) pp. 295-9. 



t Bot. Centralbl., xxxv. (1888) p. 221. 



i Bull. Soc. Bot. France, xxxv. (1888) pp. 251-6. 



