29 



Teleutospores are practically the rest, or resting, spores of 

 Puccinia graminis, in which form the fungus is carried through 

 the winter. They do not germinate at once, at least naturally, 

 and go through the winter on the infected straw, or grasses. It is 

 not known whether they "rest" on the ground, or in other 

 places where they may have been carried by the wind and other 

 agencies. 



De Bary says : " Teleutospores of Puccinia graminis which 

 have lasted during the winter germinate with great readiness in 

 the spring which succeeds their period of ripeness ; more slowly 

 and more infrequently during the following summer months, 

 and I was unable to procure their germination after August, or 

 in the spring of the second year."* 



Marshall Ward, on the other hand, gives a figure of four 

 teleutospores germinating, of which he says, " the one to the 

 top, and that to the right hand had been kept for three years in 

 my laboratory."t 



The teleutospores are, at all events, upon the straw, upon the 

 stubble, and upon numerous grasses ; J but in this form tney will 

 not germinate upon corn and grass plants. So far, as is known, the 

 Puccinia graminis can only be reproduced, and its life history 

 completed, in this country at least, by means of the barberry, 

 upon whose leaves the teleutospores germinate, by putting 

 forth from their cells germ-tubes, like hyphae, forming the 

 promycelia producing sporida, which penetrate the epidermis 

 of the barberry leaves, and, like the potato fungus, Phytophthora 

 infestans, establish mycelia in the parenchyma. 



In due course the aecidium form, sEcidium berberidis, is 

 evolved from these mycelial centres, and the ascidiospores are 

 distributed over the land in the same manner as the spores of 

 the fungus which attack the potato plant, and those of other 

 destructive fungi. 



The ^Ecidiospores germinate and produce uredospores upon 

 wheat, oats, and rye -plants, and many grasses. Oat plants, 

 fortunately, are not materially injured in this country, but in 

 other countries, as Germany, Russia, Sweden, Norway, with 

 others, both oat and rye plants are as much affected as wheat 

 plants. The injury caused to oats and rye is similar to that 

 caused to wheat ; the straw is blackened and deteriorated in 

 value, and the grains are shrivelled, small, and deficient in 

 starch. 



Comparative Morphology of the Fungi, Jfycetozoa, and Bacteria, by 

 A. De Bary, 1884. 



f Illustration of the Structure and Life History of Puccinia Graminis, the 

 Fungus causing the Rust of Wheat, by H. Marshall Ward, M.A., F.R.S., 

 F.L.S. Annals of Botany, vol. ii. 



J Mr. Plowright gives a list of thirty-two grasses which are hosts of 

 Puccinia Graminis. Among these are rye grass, couch glass, and other 

 common grasses in fields, meadows, aod hedgerows. 



De Bary says that " If the tube receive sufficient nourishment it 

 developes directly in many cases into a mycelium or thallus, like that of 

 the parent, and it is therefore the primordium of the mycelium." Op. cit. 



