ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 469 



(8) The varieties Coremium and Coremioides, which occur not only in 

 Penicillium, but also in Verticillium and Aspergillus, become more per- 

 sistent by the aggregation of fertile filaments, until the spores of a 

 Coremium reproduce the same form even in conditions in which at first 

 it would not have been produced. 



(9) The purpose of the Hyphomycetes in the economy of nature 

 appears to be to prepare dead or dying organic substances for the attack 

 of the Schizomycetes by which their putrefaction is accomplished. 



(10) If species of Hyphomycetes are transplanted singly into an 

 Erlenmeyer's chamber containing a sterilized substratum, and are then 

 infected by Micrococcus prodigiosus, they do not appear to experience any 

 evil effects in their development, but in time cover the whole surface of 

 the culture, and exhibit well-developed sporophores. 



Cultivation of Phycomycetes.* — Herr W. Zopf recommends the 

 following method for the cultivation of Chytridiacere, Saprolegniese, and 

 Monadineaa. He covers the surface of the water with pollen-grains 

 (those of Conifers are best), or spores of ferns or fungi. The zoospores 

 of the Phycomycetes attack these anddevelope in them, and their growth 

 can be readily watched. He has followed in this way the development 

 of Bhizophidium pollinis, and of four new species, Lagenidium pygmseum, 

 Bhizophidium Sphserotheca, B. Cyclotellse, and Bhizophyton Sciadii. 



Herr Zopf finds Bhizophidium pollinis to be not epiphytic, but 

 parasitic, with an endophytic mycelium. Besides the well-known 

 zoospores, he finds large resting-spores. The escape of the zoospores 

 takes place through several openings. It attacks the pollen-grains of 

 many Angiosperms and Gymnosperms. 



Bhizoplnjton Sciadii attacks the cells of Sciadium arbuscula. Its 

 zoospores attach themselves, and put out a branched mycelium into the 

 cell-cavity of the host, forming zoosporangia externally which open by 

 an apical pore. No resting-spores were observed. 



Bhizophidium Sphserotheca was observed on the microspores of species 

 of Isoetes ; the course of development resembles that of B. pollinis, but 

 the zoospores are smaller. Besting-spores were not observed. B. 

 Cyclotellse does not attack pollen-grains, but is a parasite on Cyclotella. 

 The zoospores are very minute, from 1*8 to 2*5 fx; the sporangia open 

 by from 1 to 3 orifices. 



Lagenidium pygmseum was found on pollen-grains of Pinus Laricio 

 and allied species. The mycelium developes in the interior of the 

 pollen-grain and puts out a perforating tube, which often branches and 

 then developes into a globular zoosporangium. The zoospores are 

 biciliated. The mycelium of the sexual generation is stouter, and soon 

 divides into an antheridial and an oogonial cell. The latter rounds 

 itself off, while the former puts out a conjunction-tube which penetrates 

 the oogonium ; and the oospore results from the passage of the whole 

 contents of the antheridium. 



Pleospora.t — Dr. A. N. Berlese gives a monograph of this genus of 

 SphaariaceaB, of which he makes 105 species, reducing to the condition of 

 synonyms a very large number of published species. He divides the 

 genus into 7 sections, as follows, viz. : — A. Sporidia transverse triseptata, 

 loculis uno alterove septis longitudinaliter divisis ; B. Sporidia trans- 



* Abhandl. Naturf. Gesell. Halle, xvii. (1887) (2 pis.). See Bot. Centralbl., 

 xxxiii. (1888) p. 325. f Nuov. Gioru. Bot. Ital., xx. (1888) pp. 1 -17G (8 pis.). 



