366 THE AMERICAN MONTHLY [Dec 



which affect the bean, pea. clover, and lady's-mantle, spe- 

 cies of Uromyces, are uni-cellular, Gymnosporangium 

 (Rostelia) growing on junipers has them two-celled^ 

 closely packed, and embedded in gelatinous substance : 

 they are prismatic, and form a compact layer in Melam- 

 spora infesting the leaves of the willow and sunspurge ; 

 and the species of Colesporium living on the colt's-foot 

 and eye-bright have four-celled telutospores united to 

 form a compact, waxy stratum, surrounded by a gelatin- 

 ous mass. The characters presented by their telutospores 

 thus form the basis of the classification usually followed 

 in this group of fungi, the spores of which, indeed, con- 

 stitute the principal feature. 



Telutospores are resting or winter spores ; only in a 

 few cases are they capable of immediate germination. 

 The name derived from telos, "end," indicates that their 

 production is regarded as completing the life cycle of the 

 fungus. Unlike other spores, which on germination give 

 rise to a branching mass of thread-like cells known as 

 a mycelium, which is really the vegetative body of the 

 fungus, a telutospore only developes a short filament or 

 promycelium, on which arises small reproductive cells, 

 the sporidia; the latter are able at once to germinate and 

 form mycelia. 



Minute yellow streaks may be observed during the 

 latter half of the year on the leaves of all our common 

 grasses, especially on the lower leaves, by anyone who 

 will take the trouble to look for them. On examining 

 these with the pocket lens they are found to be chinks in 

 the epidermis of the leaf filled with orange-coloured dust. 

 Under a microscope of low power, with direct light, a 

 small piece of grass-blade so affected presents a charm- 

 ing appearance. The dust is seen to be composed of 

 orange red globules, having a waxy lustre or bloom, re- 

 minding one of artificial fruits, and forming a splendid 

 contrast to the bright green chlorophyll grains of the 



