. The British rust fungi (Uredinales) their biology and classification. Rust fungi -- Great Britain. GERMINATION OF vECIDIOSPORES 7 tapping are mature enough to germinate, and even they, owing to their thin walls, may lose this power in a few days according to circumstances. Especially can they be killed by rapid. Fig. 5. P. Caricis. a, three cells of the peridium, on Nettle ; b, a cell in optical section; c, the same in surface-view ; d, two acidiospores. x 600. drying. Instances are known, however, where some of them, kept in a cool place, retained their capacity for germination about sevent
. The British rust fungi (Uredinales) their biology and classification. Rust fungi -- Great Britain. GERMINATION OF vECIDIOSPORES 7 tapping are mature enough to germinate, and even they, owing to their thin walls, may lose this power in a few days according to circumstances. Especially can they be killed by rapid. Fig. 5. P. Caricis. a, three cells of the peridium, on Nettle ; b, a cell in optical section; c, the same in surface-view ; d, two acidiospores. x 600. drying. Instances are known, however, where some of them, kept in a cool place, retained their capacity for germination about seventy days, though most of them were dead after eighty days. Each spore has a number of germ-pores; in Puccinia Caricis the number is about five or six; in other species of Uredinales the number varies from two to eight. These pores, which are scarcely visible until germination begins, are thin places in the inner layers of the outer wall, the whole cell bearing a close resemblance to many kinds of pollen-grains (microspores). (Fig. 6.) It is worthy of notice that in the spores of Endophyllum, and others of the less advanced type, there are no real germ- pores ; the germ-tube merely forces its way out at the first place that gives way. From this state of things there is a gradual transition from numerous to few germ-pores ; in the highest types of all (Uromyces and Puccinia teleutospores), each cell has one and only one well-defined germ-pore. Fig. 6. vEcidiospore of P. Caricis, germinating in water, x Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Grove, W. B. (William Bywater), 1848-1938. Cambridge, University Press
Size: 1791px × 1395px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishercambr, bookyear1913
