494 SUMMARY OF CURRENT RESEARCHES RELATING TO 



composed of 3 per cent, cane-sugar, ■ 5 per cent, peptone, and ■ 5 per 

 cent, beef extract ; and from this were made solutions containing various 

 gram-molecule percentages of potassium nitrate. 



Nuclear Phenomena in Ustilaginese.* — Dr. R. A. Harper states 

 that fusions of conidsoccur in Ustilago antherarum and U. Scabiosae which 

 are apparently caused by cheraotactic stimuli. In these fusions no 

 nuclear changes take place, but the cytoplasmic union of the cells causes 

 them to increase in size, and gives them power to resist unfavourable 

 conditions. He suggests that this may be a primitive or degenerate 

 sexual union. 



Proteolysis in Aspergillus niger.j — By cultivating this fungus in a 

 variety of nutrient media, Dr. G. Malfitano claims to have established 

 that there takes place in its cells a process of dissociation of the nitro- 

 genous compounds, consisting in a proteolysis, the diastatic factor of 

 which can be demonstrated in its cells and in the culture medium. The 

 secretion of this proteolytic diastase appears to be a constant fact in the 

 life of the organism ; all the external conditions which influence it act 

 at first directly on the development of the mycele. The appearance of 

 the diastase in the medium appears to be associated not with the life but 

 with the death of the cells. 



Phyllactinia4 — Herr. F. W. Neger describes in more detail the 

 peculiar contrivance, consisting of a pencil of jointed mucilaginous hairs, 

 by which the peritheces of species of this genus of fungi attach them- 

 selves to the leaves of the plants on which they grow. The arrangement 

 is found on several new species of Phyllactinia from Argentina, also on 

 Microsphsera Myo&cldli sp. n. 



Uredinese.§ — Herr H. Klebahn relates a further instalment of his 

 experiments on the culture of Uredinese, with the purpose of determining 

 the genetic relationship of the hetercecious forms. Among the many 

 interesting results may be mentioned that all the species of Melampsora 

 are not, as has heretofore been supposed, hetercecious. On species of 

 Salix he finds a parasitic fungus of this group which produces, on the 

 same host-plant, cBeuma, uredospore, and teleutospore forms. 



Parasitic Fungi. — Prof. M. C. Potter || describes a new disease of 

 the swede caused by a species of PJwma characterised by its rose-coloured 

 or carmine masses of spores. It appears to bo nearly related to P. Brassicee 

 and P. 8anguinolenta ; the three may possibly be forms of the same 

 species. 



A destructive disease of the alder in Belgium is traced by M. P. 

 Nypels IT to the attacks of Valsa oxy stoma, the structure of which, and 

 its destructive effects on the wood, are described in detail. 



* Trans. Wisconsin Acad. Soi., xii. (1899) pp. 475-98 (2 pis.). See Amer. Nat., 

 xxxiv. (1900) p. 448. t Ann. Inst. Pasteur, xiv. (1900) pp. 60-81. 



X Ber. Deutsch. Bot. Gesell., xvii. 1S99 (1900) Erganz.-Heft, pp. 235-42 (1 pi.). 

 Bot. Centralbl., lxxxii. (1900) pp. 261-4. Of. this Journal, ante, p. 94. 



§ Pringsheim's Jahrb. f. wiss. Bot., xxxiv. (1900) pp. 347-404 (8 figs ). Of. this 

 Journal, 1898, p. 569. 



|| Joura. Board of Agriculture, vi. (1900) pp. 448-56 (1 pi. and 5 figs.). 



IT Bull. Soc. Beige Micros., xxv. (1900) pp. 93-104 (1 pi.). 



