ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 69 



for the fermenting of rice, and made by Calmette the type of an inde- 

 pendent genus Amylomyces, is a true JMacor, and is named by him 

 M. Iiouxii. It ferments levulose, dextrose, galactose, sucrose, lactose, 

 maltose, aud inulin, with production of alcohol. The structure, life- 

 history, and physiological properties are described in detail. 



In another paper * the same author describes a hitherto unknown 

 species which also takes part in the fermentation of Chinese or Javanese 

 yeast, " ragi," and which he names Mucor javanicus. 



Parasitism of the Ustilagineae.f — O. Brefeld contests the ordi- 

 nary view that the parasitism of the Ustilagineee is obligatory. He has 

 succeeded in growing several species of Ustilago quite independently of 

 the host-plant ; they thrive especially in the fasces of domestic animals, 

 a point of very great importance in the spread of smut and the other 

 diseases to which they give rise in cereal crops. The author succeeded 

 also in developing these fungi in artificial nutrient solutions. 



In the case of most cereals there is only one period in which they 

 arc liable to the attacks of these parasites, viz. the earliest stages of 

 germination of the seedling, when the tissues are very soft ; after that 

 they are exempt ; but, having once entered, the fungus reaches the 

 growing point and destroys the inflorescence. The maize-smut, Ustilago 

 maydis, exhibits somewhat different properties from those of other 

 species, since it attacks not only young, but also mature plants. 



The author further determined by experiment that the spread of 

 smut is due to the power not only of the conids but also of the ustilago- 

 spores (smut-spores) of germinating and multiplying rapidly outside the 

 host-plant. 



Mycosyrinx4 — Prof. O. Penzig has had the opportunity of studying 

 JUycosyrinx Cissi, a parasitic fungus belonging to the Ustilagineae, whicli 

 attacks exclusively the flower-stalks of several species of Cissus in various 

 tropical countries. It there forms fungus-galls or mycocecidia imbedded 

 in the tissue of the peduncle, where it produces its spores ; the spori- 

 genous stroma being formed in a perfectly closed cavity. Another 

 species, M. arabica, is also parasitic on the pedicels and petioles of 

 species of Cissus in Arabia, likewise forming imbedded mycocecidia. 



Sexual Reproduction in Pyronema and the Morphology of the 

 Ascocarp. § — After a review of the researches and theories of other 

 authorities on the development and homology of the ascocarp in tho 

 Ascomycetes, Prof. R. A. Harper describes in great detail his own 

 observation on Pyronema confluens ; the sexual reproductive apparatus 

 in this genus being the largest and most conspicuous yet discovered in 

 the Ascomycetes. No trace of non-sexual reproduction by conids or 

 otherwise was detected. 



The sexual nuclei of both antherid and oogone are relatively large, 

 and are very clearly defined in their structure ; they contain a very 

 small spherical nucleole. In order for impregnation to be effected, two 

 processes are necessary. In addition to the fusion between the tip of 



* Tom. cit., pp. 610-9 (1 pi.). 



t J.B. Schles. Ges. Vaterl. Cultur, 1900, Zool.-Bot. Sect., pp. 17-32. 



J Malpighia, xiii. (1900) pp. 522-32 (2 pl.s.). 



§ Aim. of Bot., xiv. (1900) pp. 321-400 (3 pis.). 



