ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 289 



sporangiophore exhibits a new and energetic activity of growth, which 

 rapidly increases in rapidity, attains a maximum which it retains for 

 several hours with slight fluctuations, and then gradually falls to 

 zero. During this fourth period the membrane of the sporangiophore 

 assumes a slate colour, while the yellow sporangium becomes brown 

 and finally black ; the columella is formed, and the spores, the 

 formation of which commenced during the third period, arrive at 

 maturity. 



Mucor mucedo exhibits similar phenomena to Phycomyces nitens, 

 while in M. stolonifer the fourth stage is altogether suppressed. 



Remarkable Development of Aspergillus niger. * — J. B. 



Schnetzler records the remarkable development of Aspergillus niger in 

 water in which there had been a fragment of mucus from the stomach 

 of a mad dog ; the fluid contained pepsine and possessed all the 

 properties of gastric juice ; it dissolved, for example, small morcels of 

 albumen. Nevertheless the fungus developed a very abundant myce- 

 lium ; the protoplasm was not attacked by the pepsine, a fresh proof of 

 the fact that a pronounced difierence must exist, of a chemical nature, 

 between living protoplasm and ordinary albumen. 



My celial Conidia of Polyporus sulfureus.f — On this species of 

 hymenomycetous fungus, which produces the disease known as " caries " 

 in chestnuts in Italy and the Pyrenees, J. de Seynes finds all the three 

 kinds of reproductive cells characteristic of the Basidiomycetes : — (1) 

 conidia or spermatia produced on the mycelium ; (2) stylospores or 

 spermatia produced in pycnidia or spermogonia ; (3) basidiospores. 

 The mycelial conidia are produced within the tissue of the host, at 

 the extremity of longer or shorter branches of the mycelium. 



Monograph of Polyporus.l — Dr. M. C. Cooke publishes the 

 " prsecursores " of a monograph of the genus Polyporus Fries. The 

 monograph is intended to include all the scattered descriptions of the 

 species known, with measurements of the pores, &c., and critical notes 

 of the species described by Fries, Berkeley, Leveille, Montague, the 

 author, and others, as derived from authentic specimens. 



Development of Pyronema confluens.§— P. Van Tieghem has 

 cultivated this fungus with success, and watched the course of 

 development of the perithecium. The thallus is segmented and 

 anastomoses, and it occasionally produces true conidial fructifications 

 instead of perithecia. The perithecium commences its development 

 by the dichotomous ramification of the enlarged summit of a single 

 erect branch, not of two, as stated by Kihlmann and de Bary : the 

 author describes three different modes of development, dependent on 

 the external conditions. 



Van Tieghem differs from the view of these two authorities that 

 the perithecium is an organ in which a process of sexual union takes 



* Arch. Sci. Phys. et Nat., xii. (1884) p. 419. 

 t Bull. Soc. Bot. France, xxxi. (1884) pp. 296-9. 

 X Grevillea, xiii. (1885) pp. 80-7. 

 § Bull. Soc. Bot. France, xxxi. (1884) pp. 355-60. 

 Ser. 2.— Vol. V. tt 



