ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 825 



determined by microchemical means, by its appearance, by its semi- 

 fluid consistency, by tbe absence of reaction witb osmic acid, 

 Millon's reagent, and tbe salts of iron, by its solubility in water, and 

 by its assuming with iodine a mahogany-brown or brown -red colour, 

 which dissipates witb heat and reappears on cooling. The proteid 

 substances, on the contrary, become yellow rather than brown with 

 iodine, and this colour is not diminished by moderate heating. 



7. The glycogen of the Ascomycetes, at first diffused throughout 

 the whole of the young plant, as it is in the animal kingdom in the 

 foetus, soon accumulates in the asci in considerable quantity, and 

 disappears gradually as the spores ripen. 



8. It is utilized in the development of the spores. Besides its 

 eventual function of a respiratory reserve, there are good reasons 

 for supposing that in the truffles, and probably also in other Ascomy- 

 cetes, it furnishes materials for the formation of the oil of the 

 ripe spores. 



9. Around glycogen and starch are ranged some allied substances. 

 It is thus that we are led to place in contact to one another a glycogen 

 group and a starch group. We may, with Boehm and Hoffmann, rank 

 with the former the glycogen of the liver and that of the muscles, 

 xantho-glycogen, achro-glycogen, and glycogen-dextrin ; and among 

 the latter, starch, the amylo-dextrins, and inulin. 



10. Glycogen, glycogen-dextrin, starch, amylo-dextrin, and inulin 

 do not give true solutions with water ; they only form a kind of magma, 

 more or less thin, in which the greater portion of the substance 

 is mechanically suspended. This fact helps us to understand the 

 storing up of glycogen and inulin in particular cells. 



Agaricini.* — In a review of our present state of knowledge of 

 the Agaricini, S. Schulzer holds that the generic classification of 

 Agaricus according to the colour of the spores, though not a natural 

 classification, is the most convenient at present proposed. Tbe 

 division into subgenera is not so satisfactory ; and he adduces several 

 instances in which a series of forms belonging to the same species 

 must be placed some in one and some in another subgenus. 



With regard to the genera of Agaricini outside Agaricus, he con- 

 siders that there is no sufficient distinction between Cantharellus and 

 Craterellus, nor between Panus and Lentinus. Marasmius also should 

 be united with Agaricus. 



Development of Sclerotium of Peziza Sclerotiorum.t — Correct- 

 ing some mistakes in the account previously given by Brefeld and 

 Coemans, 0. Mattirolo gives the following description of the mode in 

 which the cup of Peziza Sclerotiorum is formed out of the sclero- 

 tium : — 



The sclerotium varies greatly in form ; but a cortical layer from 

 two to four cells in thickness can always be distinguished from the 

 medullary portion. The first rudiments of the cup make their appear- 

 ance in the outer medullary layers. The hyphse divide and become 



* Oesterr. Bot. Zeitschr., xxxii. (1882) pp. 186-9, 220-5, 250-3. 

 t Nuov. Giorn. Bot. Ital., xiv. (1882) pp. 200-12 (2 pis.). 



