ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 77 



Cytological Study of ChytridinesD.* — Walter Bally has made a 

 study of CkrysopMyctis endobiotka, and, for purposes of comparison, of 

 Synchytrnnn Taraxaci. He gives an account of the first appearance 

 and subsequent dissemination of the first-mentioned which causes a bad 

 disease of potato tubers. He gives a detailed account of all the stages 

 in the fungus of spore-formation and germination with the accom- 

 panying cytological changes, and sums up his observations at the end of 

 a very lengthy paper. In Syncliytrium Taraxaci, the primary nucleus 

 of the spore contained, in the young stages, a large-sized nucleolus, rich 

 in chromatin. At a later stage, this nucleolus broke up into secondary 

 nucleoli which passed into the cytoplasm as chromidia. Mitotic divi- 

 sions of the primary nucleus were not observed, unfavourable stages of 

 development only having been seen. The secondary nuclei divide 

 mitotically, and various differences are recorded. The spindle fibres are 

 of intra-nuclear origin, and arise out of linin threads. The swarm-spores 

 of Chrysophlydis possess a cilium, some small granules, and minute 

 chromatin grains ; no nucleus was distinguished. The youngest parasitic 

 stage of the fungus has a distinct nucleus with large nucleolus, and from 

 these young spore stages are formed sporangial sori and resting spores. 

 Chromatin, in the form of chromidia, passes from the nucleus to the 

 cytoplasm ; mitotic divisions of the primary nucleus were not observed. 

 The zoospores are formed in the cytoplasm independently of the nu- 

 cleus. Chrysophlyctis differs from Synchytrium in the manner in which 

 the zoospores are formed and in other particulars. 



Urophlydis Ruhi'aameni was also examined, and the successive stages 

 of growth and the nuclear changes are fully described. General com- 

 parative notes on these three members of the Chytridiaceas are given. 



Development of the Perithecium in Chsetomium.t— J. Yallory has 

 studied the formation of the ascogonium in this Pyrenomycete, and he 

 finds no trace of fusion of nuclei except in the formation of the ascus. 

 He questions the reality of the fusions reported by various workers in 

 the ascogonium of Humaria, Lachnea, etc. He thinks that the "fusions" 

 are probably examples of amitosis with the daughter-nuclei shghtly 

 separated. 



Ergot of Grasses.^ — The well-known Ergot is a parasitic fungus 

 {Claviceps purpurea) on grasses and cereals. From the latter it has been 

 eradicated in this country, but it is still common on many grasses, and 

 sometimes causes fatal illness in cattle. If the grasses are kept from 

 flowering for two years in succession, the fungus would die out, as it is 

 developed in the young seed-vessel. 



Development of Apothecia in Lachnea scutellata.§ — W. H. Brown 

 collected his material upon decaying wood in damp places. He de- 

 scribes his methods of fixing, etc., and gives a general description of the 

 mature ascocarp. He thus summarizes his results. The ascogonium is 



* Jahrb. wiss. Bot. 1. (1911) pp. 95-156 (5 pis.). 



t Comptes Bendus, clii. (1911) pp. 1012-14. 



J Journ. Board Agric. xviii. (1911) pp. 762-3. 



§ Bot. Gaz., lii. (1911) pp. 275-304 (1 pi. and 59 figs.). 



