488 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The cell walls are seldom pierced, and the protoplasm is only slightly 

 altered in appearance ; the nuclei remain unaltered until the cells are 

 crushed. 



L. A. Hawkins * has also published an account of " leak " in potatoes 

 due to the same fungus and to Fythiimi de Baryanum, the latter being 

 the most common origin of the disease. It is of considerable import- 

 ance in California, and appears soon after harvesting in warehouses, etc. 

 At first there is a small discoloration round a wound which spreads 

 over the whole surface, and the tissues soon sol ten and shrivel. 



Microthyriaceae.f — G. Arnaud continues his study of this family of 

 microfungi. He maintains that there is frequently a mycelium pro- 

 duced external to the perithecium which creeps on the surface of the 

 leaf of the host-plant and pierces it in places. He describes this 

 mycelium and the manner of attack. Incidentally he states that Tricho- 

 thyrium is simply a Microthyrium adapted to parasitism on another 

 superficial fungus, generally Meliola. On the various characters Arnaud 

 establishes two new genera, HariotuJa and PatouiUardiana. 



Development of Yeast. J — Kendo Saito has experimented with 

 several yeasts on a large number of different culture media in order to 

 test the chemical substances that influence the formation of spores, etc. 

 He gives an historical sketch of similar work done in other groups of 

 fungi. He explains his own methods and gives full details of the 

 culture of each species. He also discusses fully the formation of spores 

 in the genus, their importance in correct diagnosis, and the conditions 

 that further or retard their growth. 



Notes on Discomycetes.§ — J. Bayliss Elliott records Orbilia curvati- 

 spora, new to Britain, and found by her in Warwickshire and Hampshire. 

 The ascomata are pale when young, but become pale apricot when older. 

 On pine logs she found another Discomycete, evidently identical with 

 iSarea pinea Bon., which she now places in BelonUUum, and publishes a 

 complete description. Two species of Ombrophila were found on alder 

 catkins in December, and accompanying one of them, Ombrophila 

 almella, she discovered a pycnidial form hitherto undescribed. The 

 pycnidium is excipuliform and forms the type of a new genus, 

 Acleistia alniella. The spores are simple and colourless, and, vviien 

 mature, stream out in a gelatinous mass. 



Observations on the Oak Oidium.|| — ^F. W. Neger had declared his 

 opinion that the Oid/'um from Rub us might l)e identical with that on the 

 oak, but by cultures, etc., he has become convinced that they are distinct, 

 though it is possible to cultivate Oidiuni Ruborwn on the oak. 



* Journ. Agric. Research, vi. (1916) pp. 627-40 (1 fig.). See also Bull. Agric. 

 lutell. Rome, vii. (1916) p. 1711. 



t Comptes Rendus, clxiv. (1917) pp. 888-90. 



X Journ. Coll. Sci. Tokyo, xxxix. (1916) pp. 1-73. 



§ Trans. Brit. Mycol. Soc, v. (1917) pp. 417-21 (1 pi.). 



II Naturwiss. Zeitschr. Forst. Landw., xiii. (1915) pp. 544-50 (2 figs.). See also 

 Bull. Agric. lutell. Rome, viii. (1917) pp. 803-5. 



