700 SUMMARY OF CUERENT RESEARCHES RELATING TO 



Mycoderma Yeast as Sak^ Disease.* — T. Takahaski found the 

 variety of yeast, whiich he describes, iu spoiled sake. Its presence was 

 demonstrated by its oxidising energy, alcohol being transformed into 

 carbohydrates aad water. The Mycoderma is formed of elHpsoid, rarely 

 globose cells. It has been named Mycoderma saprogenes sake. 



Penicillium crustaceum.f — P. Schiirhoflf contributes a cytological 

 study of the conidial form of this fungus. He describes his methods of 

 culture and fixation of the fungus and then gives his observations on 

 nuclear division. This is preceded by the formation of two chromosomes 

 which divide to form four daughter-chromosomes ; a spindle is also 

 found to lie between the two groups of chromosomes. As soon as the 

 spore nucleus passes into the newly formed spore a new division begins 

 in the sterigma. 



Hyphomycetes.J — Gr. Lindau completes in this number the section 

 of Phffiodidymae, publishing therewith an index of the genera dealt with 

 and also an index of the illustrations. He begins a new volume with 

 the Phgeophragmias, and describes the Clasterosporiete and part of the 

 Septonemese. In a short preface he speaks of the difficulty he finds in 

 determining the plants imperfectly described by old writers. Lindau 

 pays particular attention throughout the work to species that are 

 parasitic on the higher plants, causing disease of the tissues. 



Influence of Locality on the Development of the Peridium in the 

 TJredine8e.§ — Boris Iwanoff has taken the changes occurring in the 

 peridial cells as an indication of the influence of environment on growth. 

 He tested first the effect of temperature, and found that the presence or 

 absence of sunlight had a marked influence on the duration of the 

 incubation period of the spores. It was much shorter in sunlight, and 

 low night temperatures also retarded development of the uredospores. 

 He then examined and measured a large series of the peridial cells of 

 /Ecidia on many different hosts. He divides the depth of the whole 

 cell by the depth of the outer and inner wall, and compares the quotients 

 one with another. He thus finds that the plants in dry or fresh soil 

 with xerophilous leaf -structure have a quotient under 2 with a few 

 exceptions. The plants on damp soil or on water-plants with hygro- 

 philous structure in the leaves have a quotient over 2, again with a few 

 exceptions. Plants growing in woods have with hygrophilous structure 

 always a quotient over 2. In measuring the cells of the host-plants, he 

 finds that xerophilous species have always a quotient under 2. The 

 parallelism is very marked when species are taken that grow on the same 

 genus of host-plants. The paper is illustrated throughout by drawings 

 in the text of the host-cells and the peridial cells, and the different sizes 

 of cells, walls, and lumen are given with the quotient in each case. 



,* Bull. Coll. Agric. Imp. Univ. Tokyo, vii. 1 (1907) pp. 101-9. See also Bot. 

 Centralbl., cv. (1907) p. 246. 



t Beih. Bot. C'.entralbl., xxii. (1907) pp. 296-8 (1 pL). 



X Rabenhorst's Kryptogamen Flora, i. Abt. 8, Lief. 105 (Leipzig, 1907) 

 pp. 833-52 ; and Abt. 9, pp. 1-48. 



§ Centralbl. Bakt., xviii. (1907) pp. 265-88, 655-72 (44 figs.). 



