96 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the comparatively largo apothecia sometimes found beneath the surface 

 ought to be connected with the exterior by some chimney-like tubo. 

 This is not the case. They appear to grow from tho inside outwards, not 

 from tho outside inwards. The fact is that a largo number of excessively 

 fine gonidia-bearing hyphffi insinuate themselves in the rock, and ramify 

 under the outer pellicle of rock as the roots of grass in a meadow. Tho 

 system can bo demonstrated by dissolving away the rock in hydrochloric 

 acid, which leaves the spreading hyphae and their gonidia iutact. This 

 internal thallus is of great importance as a silent factor in dynamical 

 geology, aiding very powerfully the weathering of rock surface. 



Lichens on unusual substrata.* — Herren Hegetschweiler and 

 Stizenberger give a list of fifteen species of Lichen gathered on serpen- 

 tine, nine on the stem of the grape-vine (besides two mosses Orthotriclium 

 ajjine and Amblystigium riparium), and eighteen on the deciduous bark of 

 young plane trees. 



Fungi. 



Accumulation and Consumption of Glycogen by Fungi.f — Dr. L. 

 Errera adduces further evidence of the fact that glycogen plays the 

 same part in fungi that starch does in other plants. In young Ascomy- 

 cetes (Peziza vesiculosa) the glycogen is distributed through the whole 

 tissue, the hyphae and pseudoparenchyma being completely filled by it. 

 As soon as the hymenium is developed the glycogen pours into it, and 

 later is found at work entirely in the asci. When the fructification is 

 ripe, the glycogen has again completely disappeared, reserve-substances, 

 especially of an oily nature, being stored up in the ascospores. The 

 same phenomenon of the disappearance of the glycogen takes place 

 during the very rapid growth of the stalk of Phallus impudicus. 



The glycogen of fungi is not formed, like the starch of other plants, 

 from the free carbon dioxide of the atmosphere, but out of previously 

 existing organic carbon compounds, especially the products of decomposi- 

 tion of other food materials. 



Function of Cystids. i — Dr. E. v. Wettstein has investigated the 

 structure and function of those organs of Hymenomycetes known as 

 cystids. Various functions, such as those of antheridia, have been ascribed 

 to them. Brefeld showed that they develope (in Coprinus stercorarius) 

 from rudimentary basidia, and have an external protective function in the 

 development of spores. They are props to keep the lamella apart. 



Wettstein has been led to corroborate and extend Brefeld's conclu- 

 sions. The cystids are homologous with basidia. Their systematic 

 importance has been exaggerated. They are always closed. There are 

 two kinds : (a) with free, (b) with fixed extremities. The latter may be 

 fixed to another cystid, or may have penetrated into the tissue of adjacent 

 lamella?, or may have united with the palisades of other lamellae. As to 

 function : (1) they force the lamellaB apart, making room for spore-develop- 

 ment ; (2) they prevent the delicate membranous moist lamellae from 

 adhering together ; (3) they may also bind lamellae together. They 

 seem definable as very passive overgrown non-reproductive basidia. 



* Flora, lxx. (1887) pp. 430-1. 



t Versamnil. Deutsch. Naturf. u. Aerzte, Wiesbaden, Sept. 21, 1887. Ber. 

 Deutsch. Bot. Gesell., v. (18S7) pp. lsxiv.-viii. Cf. this Journal, 1886, p. 833. 

 X SB. Akad. Wiss. Wien. xcv. (1887) pp. 10-21 (1 pi.). 



