288 SELECTED NOTES. 



my friend who described it called them calcareous. Would some 

 of our members dry, and thus test, a piece of common Borage ? 

 If calcareous, hydrochloric acid would, I suppose, dissolve them ; 

 but if siliceous, they would, I suppose, stand the acid. A. Smith. 



-fficidium bellidis.— This illustrates one phase in the "Alterna- 

 tion of generations " in the micro-fungi. These aecidium cups or 

 " Cluster cups " may often be found on backs of leaves, especially 

 at this time of the year — indeed, it is difficult to find a leaf of 

 Coltsfoot (Tussilago farfara) which does not serve as a host for 

 them. The varieties occurring on different plants are very similar, 

 and receive their names from their host, thus — -^. tussilaginis is 

 found on the coltsfoot, JE. bellidis on the daisy, ^. primulce on 

 the primrose, and so on. The outer sheath is filled with filaments 

 and spores which separate into the minute secidiospores. They 

 are produced from individual cells at the base of the cup, called 

 " basids," though the formation, or rather the manufacture, of 

 basiospores can be much more easily demonstrated on Penicillium 

 crustacewn. 



The basiospore is also called the aecidiospore when, as in the 

 instance of the object under discussion, it is developed within an 

 ^cidium. The ripe aecidiospore germinates only on the leaves 

 and stems of grasses and such like plants, and ultimately produces 

 " Teleutospores," which are two-celled. Immediately upon ger- 

 minating, the aecidiospore generally produces one-celled spores, 

 known as " Uredospores," which germinate very rapidly and con- 

 stantly reproduce the same type. By the production of uredo- 

 spores from aecidiospores hyphae is limited, and generally only 

 teleutospores are formed. The teleutospores fall upon the bar- 

 berry, the coltsfoot, etc., and from them arise the aecidium cups. 

 It will thus be seen that two plants are necessary for the life- 

 history of these alternating organisms. 



So far as is known, the generations are perfectly asexual, 

 though rudiments of supposed sexual organs, called " sperma- 

 gones," are found on ^. berberidis^ opposite the aecidia — />., on 

 the upper side of the leaf 



These micro-fungi seem to be extra specially adapted to their 

 condition of existence. By appropriating as their pabulum the 



