4G8 SUMMARY OF CURRENT RESEARCHES RELATING TO 



for tho division of tho Agaricinca), but only retained as a generic 

 character. 



Identity of Polyporus abietinus Fr. and Irpex fusco-violaceus Fr.* 

 — II. L. Morot bad the good fortune to find in tbc forest of Senart 

 numerous specimens of Polyporus abietinus Fr. and Irpex fusco-violaceus 

 Fr., and was able to observe tbo passage of the one into tbo other, and 

 thus establish their identity. The author states that certain other 

 members belonging to the genera Irpex, Sistoirema, and Dsedalea seem 

 destined to disappear, and to belong really either to Polyporus or 

 Lenzites. 



Polymorphism of the Hyphomycetes.f — Sig. G. Gasperini has made 

 a series of experiments on tho cultivation of various fungi which he 

 classes among the Hyphomycetes, with special regard to the effects on 

 the course of development of changes in the temperature, tbe degree of 

 moisture, the nature of the substratum and environment, &c. The genera 

 chiefly experimented on were Verticillium, Penicillium, Aspergillus, and 

 Sterigmatocystis ; and the following are the more important conclusions 

 at wbich he arrived. 



(1) The degree of autonomy of the species of Micromycetes inves- 

 tigated does not differ fundamentally from that ascribed by modern bio- 

 logists to the higher organisms ; in no instance were sporophores truly 

 typical of distinct species or genera found to spring from the same mycelial 

 filament either simultaneously or successively. 



(2) All the species followed out in their natural evolution from the 

 spore to the adult plant, and to the sporigenous condition, present a 

 cycle of forms constant in proportion as the conditions of the experiment 

 were unchanged. 



(3) Species cultivated in a moist chamber with suitable substratum, 

 at the ordinary atmospheric pressure, and with abundant oxygenation, 

 exhibited peculiarities which were less marked in their natural state, or 

 of which they were altogether deficient, peculiarities which have given 

 rise to not a few errors in taxonomy. 



(4) Species growing in conditions unfavourable to their development 

 exhibit a distinct tendency to assume lower forms: — an example of 

 atavism or reversion to a primitive type. 



(5) The proportion between the luxuriance of the mycelium and the 

 number and complexity of structure of the sporophores, varies in each 

 species within wide limits. 



(6) The polymorphism of the conidial fructification, in the various 

 species examined in diverse vital conditions, remained constantly within 

 limits marked on one side by the typical form, on the other side by 

 fertile hyphre differing from the mycelial filaments, with which they 

 were continuous only in bearing one or more conidia at their extremity. 

 Between these extremes each species presented a complete gradation of 

 forms. 



(7) The fasciculate varieties of Penicillium, known as Coremium and 

 Coremioides, formerly considered to be accidental, or dependent on an 

 abundant supply of food-material, express rather a biological adaptation, 

 special and unfavourable to vital conditions, for the purpose of providing 

 for the perpetuation of the species. 



* Morot's Journ. de Bot., ii. (188S) pp. 30-2. 

 t Atti Soc. Tosc. Sci. Nat., vi. (1887) pp. 20-6. 



