680 SUMMARY OF CURRENT RESEARCHES RELATING TO 



in the cells of Stichococcus (1) a single nucleus, (2) three kinds of 

 granules, two of which are visible in the living plant. 



Salt-water Aquarium.* — Rina Scott describes an aquarium in 

 which successful experiments have been carried on for some years. The 

 sea-water can be kept fresh for years without being changed, the salinity 

 being tested by means of specific gravity balls, aud regulated accordingly. 

 The water must be well syringed daily, and all dead or decaying matter 

 must be removed at once. Periwinkles are introduced in order to devour 

 the superfluous green spores. It is possible to watch the germination of 

 spores of Florideae or other algae, by allowing such spores to settle on 

 mica plates h in. square; these plates are suspended among the fruits 

 and can be removed and placed under a Microscope at will. 



Fungi. 



Mucors of East Siberia.! — Wlad. Schostakowitsch has devoted 

 special attention to the genus Mucor in the neighbourhood of Irkutsk. 

 During his three years' residence there he found eight different species, 

 all of which he cultivated, and watched their development. The fol- 

 lowing are new to science : 31. irJcutensis, M. heterosjwrus sibiricus, M. de 

 Baryanus, and M. angarensis. 



Dematophora in Fruit.J — Ed. Prillieux has discovered the Asco- 

 mycetous fruit of the fungus Dematophora necatrix, which attacks aud 

 destroys the roots of fruit trees, but of which the perfect form has not 

 hitherto been known. Some roots infested by the fungus were kept in 

 a suitably moist condition for several years, and the mature perithecia 

 were at last produced. Careful examination proved them to belong to 

 the genus Bosellinia, and the author has given them the specific name 

 necatrix. When Prof. Hartig first described Dematophora he was im- 

 pressed by the resemblance of the hyphae to those of species of Bosel- 

 linia, and he was then of opinion that the mature fruit form would be 

 oue of that genus. The perithecia are globose, brown, about 1*5 mm. 

 in diameter. The spores are very dark coloured when mature. 



The Genus Aspergillus.§ — (J. Wehmer has published an account of 

 the above genus, with special reference to the forms that occur in 

 central Europe. The ascus fruit is known in only three or four species, 

 and the author does not think these should he placed in another genus, 

 Eurotium. He decides also that the genus Sterigmatocystis cannot stand. 

 He finds that the branching conidiophores, by which it is distinguished, 

 occur simultaneously with simple conidiophores on the same individual. 

 He has arranged the classification according to colour: green, white, 

 black, and yellow or brown. 



Fruit Yeasts.|J — W. Rommel found two wild yeasts growing in flask 

 beer that had been kept for some time, and, in order to discover their 



* New Phytologist, i. (1902) pp. 124-6. 



t Zeitschr. aDgew. Mikr., viii. (1902) pp. 02-5. 



J Comptes Rend us, exxxv. (1902) pp. 275-8. 



§ Mem. Soc. phys. et hist. nttt. Geneve, xxxiii. (1901) pt. 2, No. i (5 pis.). Cf. 

 Centralbl. Bakt., ix. (1902) pp. 173-5. 



|| AVochenschr. f. Brauorei, xix. No. 12, pp. 176-S. See also Centralbl. Bakt., ix. 

 (1902) pp. 170-1. 



