ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 729 



sence of glucose in the chitinous covering of the insect, located at the 

 place of insertion of the muscles, or spread over the whole surface. He 

 finds in the existence of this sugar, a reason why so many fungi grow 

 readily on insects : Saprolegnieas, Laboulbeniaceaa, and several Hypho- 

 mycetes. Where a sclerotium is formed in the body of the insect, as in 

 Gordyceps, the outer chitinous covering must play an important part in 

 nourishing the ascus form of fruit. 



Biology of Ergot.* — R. Stager gives the results of his infection 

 experiments with Claviceps. The forms that grow on Brachypodium 

 silvaticum also infect Milium effusum, but only the Sphacelia condi- 

 tion was developed. In tracing the life-history of the fungus, he found 

 that the infection of the flower of Milium effusum is caused by the Asco- 

 spores of Claviceps Brachypodii ; the conidia formed on Milium then 

 infect Brachypodium silvaticum, in the flower of which the Sclerotium 

 is formed. It was also possible to produce the Sphacelia stage on Poa 

 pratensis and P. trivialis. 



Phyllactinia Corylea.f — P. Voglino publishes a full account of the 

 morphology of this fungus. He describes its development in the leaf 

 and its action on the leaf tissue. Although it is usually superficial, 

 some of the hyphse penetrate through the stomata and cause a dis- 

 coloration of the host-cells. He draws special attention to the needle- 

 like appendages of the perithecium and also to the attaching filaments, 

 hypha? that rise from the base of the perithecium and branch out into a 

 pencil-like head of elongate cells all equal in length. He proposes to 

 call them epipectic hyphae (ife epipecteche) : they serve to keep the fruits 

 attached to the leaf during the winter, and so secure early infection of 

 the host-plant in spring. Voglino tried infection experiments with the 

 ascospores from one host to another, without result. There is, probably, 

 specialisation in this genus similar to that which has been proved in 

 other members of the Erysiphaceas. 



Morphology and Cytology of Yeasts.J — A. Guilliermond gives a 

 description of the development of the yeast-cell, especially of sporula- 

 tion and conjugation. Caryogamy is wanting at the origin of the ascus 

 in Saccharomyces ; conjugation takes place before sporulation in Zygo- 

 saccharomyces and Schizosaccharomyces. In the latter apogamy has also 

 been noted. In Saccharomyces Ludivigii two spores fuse before ger- 

 mination, and an ascus has sometimes been formed as the result of this 

 conjugation. The author considers that the Schizosaccharomycetes are 

 connected with the Saccharomycetes by the genus Saccharomy codes. 

 Their connection with the Bacteria is problematic. 



Vacuoles in Yeast-Cells.§ — An examination of yeast-cells has led 

 J. J. Van Hest to believe that they do not contain vacuoles, but that 

 the appearance so described is due to flattened portions of the cell-wall. || 



* Centralbl. Bakt., xiv. (1905) pp. 25-32. See also Bot. Zeit., lxiii. (1905) p. 216. 



t Nuovo Giom. Bot. Ital., xii. (1905) pp. 313-27 (8 figs.). 



% Bull. Inst. Pasteur, iii. (1905) pp. 177-84 and 225-35 (figs. 1-21). See also 

 Bot. Centralbl., xcix. (1905) p. 164. 



§ Wochenschr. Brauerie, Bel. xxii. No. 8, p. 105. See also Centralbl. Bakt., xv. 

 (1905) p. 61. 



|| Tom. cit., No. 9, p. 123. See also Centralbl. Bakt., xv. (1905) p. 61. 



