EU-MYCETES. (b) BASIDIOMYCETES 



445 



the uredo-spores and teleuto-spores are on leaves of species of Carex, 

 and the aecidium-stage on the common Nettle, causing contorted 

 swellings upon its stem and leaves. Thus the Rust of Wheat is an 

 example of a life-history that is not uncommon. 



FIG. 379- 



Longitudinal section of a leaf of Wheat, showing a germ-tube of a Uredo-spore 

 passing through a stoma (a) into the intercellular space (fc). Very highly magnified. 

 {After Marshall Ward.) 



Sections through a diseased leaf of wheat in summer reveal the 

 branched and septate hyphae closely packed in the inter-cellular 

 spaces, and investing the green cells. They accumulate below the 

 epidermis, forming a spore-bed, their endings swelling into the uredo- 



FIG. 380. 



Longitudinal section through a patch of the Teleuto-spores of Puccinia, on a stalk 

 of Wheat-straw. Highly magnified. (After Marshall Ward.) 



spores, which, increasing in bulk and number, burst the epidermis, 

 and are shed (Fig. 377). Each spore is covered by a thick wall, 

 containing dense protoplasm with oily globules, and two nuclei. Their 

 walls are marked by thin spots round the equator. It is from these 



