ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 493 



Herr C. Ostenfeld * has now slightly changed his systematic classi- 

 fication of these bodies. The genus Coccosphsera includes V. pelagica 

 Wall., C. atlantica Oat. (= G. pelagica M. and B.), and C. leptopora M. 

 and B. The family Bhabdosphaerales includes two genera : Bhabdo- 

 sphseva, with the single species B. claviger M. and B. (syn. B. Murrnyi 

 Ost.) ; and Discosphaera, with the single species D. tubifer ( = Bhabdo- 

 sphxra tubifer, = Discosphaera Thomsoni). 



Fungi. 



Fungi in Dwellings.! — Herr G. Marpmann treats of the fungi in- 

 jurious to health found in human dwellings, which may be either in 

 themselves pathogenic, or may produce poisonous products of decompo- 

 sition, which are given off into the air, or which produce poisonous pro- 

 ducts from certain special substances which they decompose, especially 

 compounds of sulphur and arsenic. By far the largest number of these 

 fungi are found on or in wall-papers, and the author gives a list of 24 

 species of fungi which were detected in these situations. 



Fungi in Oil.J — Experiments carried on by M. L. Lutz show that 

 the growth of fungi — chiefly Pholiota mutabilis, Qantharellus cibarius, 

 Hypholoma fasciculare, and Clavaria formosa — is affected very differently 

 by different kinds of oil. In castor oil the growth was but slightly 

 modified, while in vaselin oil or sweet almond oil very great changes 

 were produced ; the filaments were niontly excessively hypertrophied, 

 and the hyphae greatly contorted and often anastomosing, with frequent 

 production of chlamydospores. This was especially the case with 

 Aspergillus repens. The difference is attributed by the author to the 

 degree to which the different oils undergo chemical change in contact 

 with the atmosphere. 



Turgidity in Myceles.§ — Mr. C. G. Curtis thus summarises the 

 result of his observations on this subject. The hyphaa of fungi possess 

 remarkable powers of adaptation, bxit show considerable variability in 

 this respect. The turgidity varies even under uniform conditions. Tie 

 moment of recovery from a change of concentration can be accurately 

 noted, since it is indicated by an apical enlargement preceding the elonga- 

 tion of the hypha. Changes from a higher to a lower concentration of 

 the substratum resulted in a steadily increasing period of recovery in 

 proportion to the concentration. Becovery from a change from a higher 

 to a lower concentration was controlled only to a limited extent by the 

 degree of concentration ; but there was also to be observed an individu- 

 ality peculiar to the genus employed, which brought about these changes 

 in shorter or longer periods of time. The turgidity of a plant recovering 

 from a change of concentration is the same as that of a plant germinating 

 and growing in the concentration to which the trial plant had been 

 changed. Turgidity appears to be a regulatory force. 



1 he fungi employed were species of Mucor, Botrytis, and Penicillium. 

 The basis of all media used in the experiments was a nutrient solution 



* Zool. Anzeig., xxiii. (1900) pp. 19S-200. 



f Zeitschr. f. angew. Mikros., v. (1900) pp. 297-308. 



t Bull. Soc. Bot. France, xlvii. (1900) pp. 76-82 (6 figs.). 



§ Bull. Torrey Bot. Club, xxvii. (1900) pp. 1-13. 



Aug. 15th, 1900 2 L 



