ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 189 



air and was previously not unknown, but no iructiiication had so far 

 ])een observed. It forms a delicate mycelium which stains the sub- 

 stratum a purple-red, the colouring- matter being dissolved in the cell- 

 sap. On a bread-culture i>ennnce are formed, which usually occupied 

 a terminal position. Conidia are also produced terminally or laterally 

 thouo^h very rarely; they have a yellowish-l)rown v^aW covered with 

 small warts. 



Study of Fusarium.* — It was proved l)y Appel and Wollenweber 

 that Fusarium roseum was a composite species. This judgment has 

 been confirmed by Jaczewski who has made cultural studies of a 

 numl)er of forms, some of them taken from ears of corn. He concludes 

 that a thorough study of the whole genus is necessary leased on pure 

 cultures. 



Spore-formation in Rust and Smut Fungi. t — E. AVerth and 

 K. Ludwig have made a comparative study of spore-germination in 

 UstilaginctT and Uredineie to determine if possil)le the relationship 

 between the two families. Ustilago antherarum and Puccinia Jlalvace- 

 arum were the two fungi experimented with. In Ustilago the authors 

 were unal )le to determine the bi-nucleate condition of the spores affirmed 

 by Dangeard, l)ut the spore-nucleus divides on germination and one passes 

 over into the promycelium while the other remains behind. When 

 secondary conidia are formed the same process is followed, that is 

 division of the nucleus with one daughter- nucleus entering the coni- 

 dium and the other remaining in the cell of the promycelium. 



In Puccinia Molvacearum the cells of the mycelial tissue are at first 

 uninucleate. By the fusion of two cells a Ijinucleate condition arises 

 and continues in all the cells produced thereafter, through conjugate 

 division of the nuclei. Fusion of nuclei takes place very late in the 

 teleutospore, when the promycelial uninucleate-cells produce sporidia ; 

 the single nucleus passes over into the sporidium, differing in this 

 from Ustilago^ in which division of the nucleus takes place first and in 

 which one nucleus remains behind. 



The authors sum up the conclusions at which they have arrived from 

 the observations made. The Uredinete have all sprung, they consider, 

 from a simple form, and the single spore-form of EndophyUum is rather 

 an yecidiospore than a teleutospore. They repeat that they were never 

 able to demonstrate the fusion-stage in the cells of Ustilago. 



Uredinese.l — R. G. Fragoso has written a general account of the 

 biology, classification, and occurrence of the Uredinese. His review in- 

 cludes every aspect of the study of the group, their vegetative develop- 

 ment, their reproduction, and their biology, with details of results obtained 

 by workers on the problems involved. The geographical distribution is 

 also discussed, and their occurrence on the various host-plants. A 

 copious bibliography is added. 



=^ Bull. Soc. Mycol. France, xxviii. (1912) pp. 340-8 (4 figs.). 



t Ber. Deutsch.Bot. Gesell., xxx. (1912) pp. 522-7 (1 pL). 



X Junta Para Ampl. Estud. Invest. Cient., viii. (1912) pp. 181-258. 



