ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 211 



•germ-tube is short ; it* they are placed in water, the promycelium con- 

 tinues to grow until it emerges from the drop of water. Sporidia are 

 never produced except in the air ; as they are wind-borne this condition 

 ,is essential. 



Research on Basidiomycetes.* — Rene Maire follows Brefeld in his 

 classification, including the Uredinete under the Proto basidiomycetes. 

 He gives a historical account of work done on the cytology of the group, 

 .and carefully details his methods of fixing, staining, &c. Maire has 

 examined a few Uredineae and a very large number of Basidiomycetes, 

 and from his extensive study he arrives at a number of general con- 

 clusions, taxonomic as well as cytological. The number of chromosomes 

 in the nucleus is invariably two, though in the basidium the first phases 

 •of division show a number of protochromosomes which later resolve 

 themselves also into two chromosomes ; the basidium in any species can 

 give rise to two generations of spores on the same sterigma. The cyto- 

 logical results have enabled Maire to group a number of families under 

 the Cantharellineas : these are the CantharellaceEe, Clavariaceas, Hydna- 

 •cea^, Phylacteriacea?, Peniophoracea3, and Exobasidiaceas. They have a 

 varying number of sterigmata and in other respects show a lower type of 

 •development than other Autobasidiomycetes. Maire also founds a new 

 family Vuilleminiacea? with one genus and one species, Vuilleminia come- 

 dens, distinguished by an irregular hymenium. He does not find that 

 sexuality is proved in the Basidiomycetes : his theory is that the fusion 

 •of the two nuclei which takes place in the basidium is not a case of 

 fecundation but of " mixie," a term which he uses to distinguish this 

 phenomenon. 



Dry-rot and other Wood-destroying Fungi, f — In this treatise 

 Robert Hartig gives an account of dry-rot, Merulius lacrymans ; the 

 extent and nature of the injury caused by it ; the development of the 

 fungus in the woodwork of buildings ; with advice as to the best means 

 •of preventing or getting rid of the pest. Polyporus vaporarius is also 

 shortly described. The author considers it much less harmful than 

 Merulius lacrymans. 



Spore -formation in Gastromycetes. $ — L. Petri publishes an 

 account of his research on the development of the basidia and spores 

 •of Hydnangium carneum. He finds that while the cells of the vege- 

 tative hyphas may have either one or two nuclei, the hyphee which are more 

 directly connected with the formation of the spores are binucleate. 

 These two nuclei fuse, giving off at the same time granules which move 

 to the tip of the basidium, and which aid in the formation of the sterig- 

 mata or of the spore involucre ; the fused nucleus then divides simul- 

 taneously into four daughter-nuclei which are connected by fibrils, 

 probably of nuclear origin, with the granules. By means of the fibrils 

 part of the chromatic substance of the nuclei of the basidium passes into 



* Bull. Soc. Myc. de France, xviii. (1902) 211 pp. (8 pis.). 



t ' Der echte Hausscbwanim und andere das Baukolzzerstorende Filze,' 2. Aufl. 

 'bcarb. und herausg. von Dr. C. Freiherr von Tubeuf, Berlin (1902). 165 pp. and 

 33 figs. See also Hedwigia, Beibl. xli. (1902) pp. 233-7. 



% App. al Nuovo (iiorn. Bot. Ital., ix. (1902) pp. 499-514 (1 pi.). 



p 2 



