. Botany for high schools and colleges. Botany. 248 BOTANY. consists of a rounded oosphere situated within a cavity—the oogonium; it is deTeloped from one of the cells (sometimes two) of the filament by a condensing and rounding off of the protoplas- mic contents; when the oosphere is ful- ly formed, an open- ing is formed in the oogonium-wall for the ingress of the spermatozoids {A and B, Fig. 167). One or more spermatozoids are produced in each of certain small cells which are formed from the large ones by a process of simple fission; in shape they resem- ble the zoospores mentioned above— t
. Botany for high schools and colleges. Botany. 248 BOTANY. consists of a rounded oosphere situated within a cavity—the oogonium; it is deTeloped from one of the cells (sometimes two) of the filament by a condensing and rounding off of the protoplas- mic contents; when the oosphere is ful- ly formed, an open- ing is formed in the oogonium-wall for the ingress of the spermatozoids {A and B, Fig. 167). One or more spermatozoids are produced in each of certain small cells which are formed from the large ones by a process of simple fission; in shape they resem- ble the zoospores mentioned above— that is, they are oval and provided with a crown of vibratile cilia on their smaller ex- tremity {D, z, z, Pig. 167). Upon escaping into the water, which is ren- dered possible by a splitting of the wall of the mother- cell, they swim about vigorously, and eventually make their way through the opening in the oogonium, and then bury. Fig. 167.—A, middle part of a eexual filament of (Edo- gonium ciliatum {Androg^nia of Wood), with male cells above at m; og, oogonia (fertilized) ; m, dwarf male plants attached to the side of the oogonia, the sperma- tozoids already discharged. X 250. B, oogonium, og, at the moment of fertilization ,* o. the oosphere ; a, the Bpermatozoid forcing its way into the oosphere; m, the dwarf male plant. 6', ripe oospore. D, (Edogonium gemelUparwm (Pringe/ieimm of Wood), part of the male filament, with spermatozoids, s, issuing from the cells. Ey part of a branch of Bulbockcete intermedia, with oogo- nia, the uppermost containing an oospore, the middle one with an oospore escaping, the lower empty. F, four zoospores resulting from an oospore of BvlbocluEte. O, zoospore come to rest and germinating.—After Prings- 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 Bessey, Char
Size: 1211px × 2064px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1888
