ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 629 



sclerotia on it. Peziza mycetophila, which grows in its conidial form on 

 Ladarius vellereiis, is known, not only in its pezizoid, but also in its 

 conidial form as Monilia alho-lutea, and as a sclerotium. When the 

 sclerotium germinates, it gives birth not to a fructification, but to a 

 mycelium. In Saccohokis depauperatus the whole membrane of the aseus 

 is coloured an intense blue by a solution of iodine. 



rormation of two fertile hymenia in Polyporus applanatus.* 

 — M. E. Heckel describes a specimen of Polyporus applanatus with a 

 double hymenium. The first hymenium, which was normal, was more 

 developed than its congener situated on the opposite side of the same 

 pilous. The second hymenium, which was formed of short oblique 

 tubes, was less than half as thick as the former. The most remarkable 

 fact about this monstrosity was that the two hymenia were both fertile, 

 though 60 diflferent. 



Stretching of the Receptacle of the Phalloidei.t — Herr E. Fischer 

 has investigated the cause of the remarkably rapid extension of the 

 receptacle of the Phalloidei, by which the volva is burst, and the mass 

 of spores raised up. The observations were made chiefly on Phallus 

 impudicus, but the explanation probably applies to the other species also. 



The extension is well known to be accompanied by a smoothing out 

 of the previously folded or plaited walls of the chambers of the recep- 

 tacle ; and De Bary attributes this to the inflation of the chambers by 

 air. Herr Fischer does not consider this explanation adequate. He 

 suggests that the folding of the walls is due to their rapid growth, while 

 the extension of the stalk is prevented by the surrounding tissue. The 

 cells which lie on the concave side are thus arrested in their growth, 

 and become extremely compressed. As soon as the pressure is removed 

 by the severance of the connection with the surrounding tissue, the 

 tension causes a sudden smoothing out of the walls of the chambers, and 

 a corresponding increase in their size ; and this is no doubt assisted by 

 the entrance of air into the chambers, which probably at first takes place 

 from the intercellular spaces of the sui-rounding tissue. 



Revision of the Genus Bovista.| — Mr. G. Massee gives a diagnosis 

 of the genus Bovista, and also descriptions of thirty-nine species, several 

 of them new. Although allied to several genera, it has perhaps the most 

 affinity with Lycoperdon, the points of difference between the two genera 

 being that in Bovista the cortex is free, and falls away in patches, the 

 sterile base is absent, and the capillitium springs from every portion of 

 the inner wall of the peridium ; while in Lycoperdon the cortex becomes 

 broken up into warts or spines, the sterile base being present. The 

 author subdivides the genus Bovista by means of spore characters : — 

 (a) Spores globose, warted or spinulose. (&) Spores globose, smooth, 

 (c) Spores elliptical, (d) Species in which information about the spores 

 is wanted. 



Formation of the Asci in Physalospora Bidwellii.§ — M. Frechou 

 states that since the black rot was noticed on the vines in France, in 

 1885, by MM. Viala and Eavaz, only the festival forms of the parasite 

 had been studied. Towards the end of June, at Nerac, shortly after the 



* Eev. MycoL, x. (1888) pp. 5-6. 



t MT. Naturf. Gesell. Bern, 1887 (1888) pp. 142-57 (6 figs.). 

 X Journ. of Boi, xxvi. (1888) pp. 129-37 (1 pL). 

 § Comptes Keudus, cvi. (1888) pp. 1361-3. 

 1888. 2 X 



