Fungi, Ascomycetes, Ustilaginales, Uredinales . the suggestion was long ago made that theymay be male reproductive elements, and this is borne out by their largenuclei and lack of reserve material, and is by no means invalidated by thefact that they possess some slight power of germination. Recent investigationhas shown that they are now no longer functional. As a rule considerable numbers of spermatia are to be found in variousstages of degeneration scattered around the ostioles of the some cases the spermatia are aggregated in sticky masses and appearto attract insects. The pr
Fungi, Ascomycetes, Ustilaginales, Uredinales . the suggestion was long ago made that theymay be male reproductive elements, and this is borne out by their largenuclei and lack of reserve material, and is by no means invalidated by thefact that they possess some slight power of germination. Recent investigationhas shown that they are now no longer functional. As a rule considerable numbers of spermatia are to be found in variousstages of degeneration scattered around the ostioles of the some cases the spermatia are aggregated in sticky masses and appearto attract insects. The presence of sugars in the spermi>L,rnial contents hasbeen demonstrated for species of I rromyces, Puccinia, Endophyllum, andGymnosporangium; in some cases the spermogonia also possess a strongodour as in Puccinia suaveolens, or occur on bright spots which contrastwith the green of the surrounding tissue. Such spots are usually yellow ororange, but are white in Uromyces Fabae and reddish-purple in Puccinia 200 PROTOBASIDIOMYCETES [ Phragmitis. A corresponding discoloration takes place around the youngaecidia, and there is thus some suggestion that the spermatia, when functional,were carried to their destination by insects. The aecidia occur in groups, usually on the abaxial side of the leaf; in them the aecidiospores areproduced in basipetal rows(fig. I/O) alternating withsmall, abortive, intercalarycells, by the disintegration ofwhich they are set free. Theymay be carried to consider-able distances by the wind,and there is evidence thatthey are sometimes distri-buted by means of insects orof snails. The mature aecidio-spore is usually subgloboseor polygonal in form, it isenclosed in a thick wall per-forated byseveral germ-pores,and contains red, yellow ororange pigment, and alwaystwo nuclei. In germinationa hypha is put out whichenters the host plant throughone of the stomata and sopenetrates into the inter-cellular spaces. The development of theaecidium begins by the mass
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectfungi, bookyear1922
