The microscope and its revelations . f the two cells (Eig. 77, d, e). Through this tubethe entire endochrome of one cell passes-over iuto the cavityof the other (d), and the two are commingled so as to form asingle mass (e), as is the case in many of the ConjugatecB(§ 199). The joiat which contams the sporangium can scarcelybe distinguished at first (after the separation of the emptycell), save by the greater density of its contents; but theproper coats of the sporangium gradually become more distinct,and the enveloping cell-wall disappears.—The subsequenthistory of the sporangia is still obsc
The microscope and its revelations . f the two cells (Eig. 77, d, e). Through this tubethe entire endochrome of one cell passes-over iuto the cavityof the other (d), and the two are commingled so as to form asingle mass (e), as is the case in many of the ConjugatecB(§ 199). The joiat which contams the sporangium can scarcelybe distinguished at first (after the separation of the emptycell), save by the greater density of its contents; but theproper coats of the sporangium gradually become more distinct,and the enveloping cell-wall disappears.—The subsequenthistory of the sporangia is still obscure; since, although itcannot be doubted that they give origiu to new plants resem-bling those by whose conjugation they are formed, it is notknown whether each sporangium in the first instance developesa single cell, or a brood of cells. The latter seems, from the 398 MICROSCOPIC FOEMS OF VEGETAELE LIFE. observations of Jermer and Eocke, to be the case with Clos-termm; whilst those of Mrs. H. Thomas (loc. cit.) indicate Pig. Didymopritim Grevillii .—A, portion of filament, surrounded bygelatinous envelope; b, dividing joint; c, single joint viewed trans-versely; D, two cells in conjugation; e, formation of sporangium. that it is likewise in Cosmarium, whose sporangium has beenseen by her to emit large numbers of bodies resemblingzoospores. This part of the history of the_ group is yetinvolved in much mystery; more especially since, accordingto the observations of Mr. Ralfs, there are several Desmidiacesewhich never make their appearance in the same pools for two COLLECTION OF 299 years successively, although their sporaugia are abundantlyproduced,—a circumstance which would seem to indicate thattheir sporangia give origin to some different forms. It is asubject, therefore, to which the attention of IMicroscopistscannot be too sedulously directed. 171. The Desmidiacese are not found in running streams,unless the motion of the water be very slow; but ar
Size: 1213px × 2059px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectmicroscopes, booksubjectmicroscopy
