378 SUMMARY OF CURRENT RESEARCHES RELATING TO 



found byThaxter on fruit, form small stroinata, on which are developed 

 pycnidia or peritbecia. The latter are bottle-shaped cavities containing 

 long slender asci with eight filamentous spores, at first cylindrical and 

 continuous, but later divided by septa, as in Cordyceps. 



Studies of Microscopic Fungi.* — J. Beauverie has completed his 

 studies of the " Muscardine " group, and has added a chapter defining 

 and delimiting the genus Botrytis, by describing under different genera 

 the species wrongly associated with it, such as species of Spicaria, 

 Beauveria, etc. The type of Botrytis is the well-known species B. cinerea, 

 with its groups of spores borne at the apex of special branching hyphse. 

 The author reviews and recapitulates Vuillemin's suggested classification 

 of Hyphomycetes, which is based on the manner in which the conidia 

 are borne on the hyphas, whether directly or at the apex of a special 

 sterigma. 



New Rhizosphsera.j — The genus Rliizosphsera, one of the Sphajroid- 

 acea?, was established by Mangin and Hariot in 1907. At a later date 

 Maublanc placed in the genus a fungus frequently found on withered 

 fir leaves, known as Leptothyrium Pinl. A somewhat similar fungus was 

 submitted to Bubak, and was determined Phoma Pini, as it occurs on the 

 needles of Picea. He now places the fungus as Rliizosphsera TcalTchqffii 

 nov. nom. The pycnidia arise on all four surfaces of the needle in 

 superficial rows. They have a flat base, and from the centre of the base 

 is formed a stalk of elongate brown kyphfe, which penetrates the leaf 

 through the stoma and broadens out after gaining entrance, then forms 

 a knot of woven brown hyphaB. A diagnosis of the species is given. 



Effect of External Stimuli on Sporidia.J — W. Robinson carried 

 out a series of experiments with the germinating sporidia of Puccinia 

 malvacearum to test the effect of various stimuli such as light, etc. They 

 proved to be negatively heliotropic, though in some other fungi and in 

 Botrytis poarum no irritability to light was apparent. As regards mois- 

 ture, the tubes formed on germination tend to grow out of a drop of 

 water, but on gelatin they pierce the substratum. On contact, the tip 

 of the germ-tube swells and becomes closely applied to the epidermal 

 surface of the host or of non-susceptible plants. On the host-plant a 

 growth from the swollen tip pierces the cuticle and outer cell-wall of the 

 epidermis, and true infection takes place. There was no evidence of 

 chemotropic influences radiating from a fragment of leaf laid on a drop 

 of gelatin, nor any indication of positive chemotropism of the germ- 

 tubes towards the normal host or of negative chemotropism of the 

 germ-tubes towards fragments of non-susceptible leaves. 



Position of Sorus of Uredinese on the Leaf.§ — F. Grebelsky has 

 examined and experimented with a number of species of Uredineaj with 



* Rev. Gen. Bot., xxvi. (1914) pp. 157-68 (figs.). 

 t Ber. Deutsch. Bot. Gesell., xxxii. (1914) pp. 188-90. 

 t Ann. of Bot., xxviii. (1914) pp. 331-40. 



§ Verh. Schweiz. Naturf. Ges., ii. (1913) pp. 212-13. See also Bot. Centralbl. 

 cxxv. (1914) p. 506. 





