ZOOLOGY AND BOTANY, .MICROSCOPY, ETC. 743 



increase in size and divide ; the chromosomes could not be accurately 

 counted ; the oospheres are formed round each nucleus by a heaping up 

 of the protoplasm round the nuclei ; there are usually 10-15 oospheres 

 in each oogonium. The antheridia arise from the stalk, or from neigh- 

 bouring filaments ; the fertilising hyphae penetrate the oogonium, and 

 may branch inside, each branch travelling towards an oosphere ; the 

 male nucleus was seen in close proximity with the female, but actual 

 fusion was not observed. 



Sexuality in the Ascomycetes* — A. Guilliermond concludes his 

 long review of this subject by a study of mitosis. He gives the results 

 obtained by various authors as to the number of chromosomes that are 

 present in the different stages of division. There is undoubtedly a 

 reduction of these, similar to reduction in the sexual mitosis of the 

 Phanerogams. The first division in the ascus is heterotypic, the second 

 homotypic, the third typical. A note is added on some systematic 

 work and on the phylogeny of the group. He finds that the asexual 

 sporangium has been transformed into a conidiophore ; the gametangium 

 is replaced by a gametophore, and the sporocyst has been developed 

 into an ascus in the adaptation of the Ascomycetes to an aerial life. 



Penicillium as a Fruit Parasite.f — Decaying fruits almost in- 

 variably show more or less abundant growths of Penicillium. This has 

 been considered to be P. glaucum, and treated as a saprophyte. 

 0. Schneider-Orelli has studied the whole subject, and gives us his 

 results. He insists on the exact recognition and definition of P. italicum 

 and P. olivaceum as distinct from P. glaucum; P. italicum 1 icing the 

 form found most frequently on oranges. Schneider-Orelli had some 

 mandarin oranges sent to him from Italy, with due precaution against 

 any risk of infection after they were plucked. He soaked the skins in 

 water, with which he inoculated subsequent cultures, and obtained 

 therefrom a series of spore-germinations, yeasts, Dematium, Clado- 

 sporium, and Penicillium italicum. He thus proved that the latter came 

 with the fruits from the south, and with favourable conditions it 

 develops on and penetrates the oranges, which it finally destroys. He 

 further proved that P. italicum attacks apples and pears in more 

 northern countries, though it is essentially a southern form, and will 

 not develop at low temperatures. P. glaucum grows in extreme cold; 

 it acts as a destructive parasite of stone fruits in northern lands, but it 

 also attacks oranges, etc, from the south. P. glaucum is easily recog- 

 nised by its round conidia. The conidia of the other two forms are 

 much larger and ellipsoid in form. 



Vegetation of Morchella. — L. Matruchot % has already published 

 an account of the development of Morchella spores, and of the conidia] 

 form Gostantinella cristata. He noted at that time the Bclerotia-like 

 masses in the cultures that were formed by the agglomeration of hyphae. 

 He has recently found in nature that similar sclerotia occur in the soil. 

 At the base of the Morchella on the surface of the soil there is a fleshy 



* Rev. Gen. Bot., xx. (1908) pp. 3G4-78 (figs.), 

 t Ceutralbl. Bakt., xxi. (1908) pp. 365-74. 

 X Comptes Rendus, cxlvii. (1908) pp. 431-2. 



