900 JOUENAL OF THE ROYAL HORTICULTURAL SOCIETY. 



has studied the development from fertilisation to maturity in O.ralidaccce, 

 Linaoece, Geraniacece, Stackhoiisiacea, and fourteen corollifloral orders, by 

 modern methods of microscopy. The observations are detailed and inter- 

 esting. In Calendula one synergid divides in two cells which enlarge 

 and pave the way for the upgrowth of the endosperm into a haustorium 

 or feeding outgrowth of the endosperm cavity into the nucellus at the 

 micropyle. Micropylar haustoria are, however, when present, usually 

 developed from the endosperm, as are chalazal haustoria. In Geraniacece, 

 the haustorium is an enlargement of the suspensor in the short arm of 

 the J-shaped embryo-sac. The difierences between allied genera may in 

 some cases be greater than those of distinct orders in others ; so that 

 systematic value cannot be attached to them. The Gruinales show 

 remarkable divergence in development. — M. H. 



Red Mould on Snow. 



Snow-Mould. By Paul Sorauer {Zcit. f. Pjianz. xi. pp. 217-228 ; 

 11/1901). — Snow-mould and red snow have long found a place in the 

 books of popular science as examples of vitality of plant life. In 1848 

 linger examined snow-mould, ascribing it to a fungus, Laiiosa nicalh. 

 Apart from its interest as a snow organism there is an economic question, 

 whether it causes damage to grasses and autumn-sown cereals. Sorauer, 

 induced by recent complaints, re-examines the mould. He finds that its 

 greatest development is in time of thaw, the place most favourable being 

 under low-lying patches of snow in the cavity formed in thaw between 

 the snow and the soil ; and that snow-crushed or frost-killed vegetation 

 is preferred as a substratum. The mould forms patches like felted 

 gossamer, and produces reddish spores of the Fiisarium type, also resting 

 chlamydospores as beads on the filaments. The general dampness pre- 

 vailing in thaw favours its growth, but a low temperature is not necessary, 

 because w^hen transferred indoors it grows rapidly. Infections demon- 

 strated that young seedlings of Rye were attacked, whereas old, well- 

 rooted plants were not. The injury of cereals and grasses by frost and 

 snow and the partial blanching of plants long buried under snow render 

 them favourable to attack. The research throws light on the well-known 

 'bleached appearance and slow recovery of vegetation which has been long 

 covered with snow. As the snow disappears and the soil dries, the 

 fungus disappears, but before doing so resting spores are abundantly 

 produced. The mould is suspected to have some summer form of growth 

 unrecognised as yet. — W. G. S. 



FOKMATION OF SpORES. 



Spore Formation in Saecharomyces. By B. T. P. Barker, M.A. 



{Trans. Brit. Myc. Soc. 1900-1901). — This communication, which is too 

 technical and abstruse to be appreciated by the general reader, gives the 

 results of experiments made on spore formation in the yeast fungus. 



M. C. C. 



Germination of Spores. 



Spore Germination. By N. Schulz {Beih. Bot. Cent. bd. xi. ht. 2, 



pp. 81-97, with 8 figures). — Moss and Fern spores germinate only in the 



