. The cell in development and inheritance. Cells. 168 THE GERM-CELLS " archoplasm " of the spermatid. Suzuki's studies clearly show, how- ever, that the entire axial filament of the long middle-piece arises by the elongation of the inner centrosome, while the outer centrosome, from which the axial filament of the tail grows out, lies at the pos- terior limit of the middle-piece (Fig. 85). A nearly similar result is reached by Korff ('99) in the case of Helix. It was shown by God- lewski ('97) that in this form the axial filament likewise grows out. Fig. 85. — Formation of the spermat
. The cell in development and inheritance. Cells. 168 THE GERM-CELLS " archoplasm " of the spermatid. Suzuki's studies clearly show, how- ever, that the entire axial filament of the long middle-piece arises by the elongation of the inner centrosome, while the outer centrosome, from which the axial filament of the tail grows out, lies at the pos- terior limit of the middle-piece (Fig. 85). A nearly similar result is reached by Korff ('99) in the case of Helix. It was shown by God- lewski ('97) that in this form the axial filament likewise grows out. Fig. 85. — Formation of the spermatozoon in elasmobranchs. \^A-C, Suzuki; D, Moore; and in Helix, E-G, KoRFF.] A-D. Outgrowth of axial filament from peripheral centrosome (ci), which persists at the posterior limit of the middle-piece or connecting-piece (m). Elongation of inner centrosome {c^) to form the axial filament of the latter. E-G show similar phenomena in Helix, with casting off of the sphere (s). a. Acrosome; c 1. peripheral, and c^. inner centrosome; / flagellum; k. end-knob, derived from inner centrosome. from the centrosome. Korff's later studies show that here, exactly as in the elasmobranch, the axial filament grows out from the periph- eral centrosome and is afterward transformed into a ring (Fig. 85). The inner centrosome elongates to form a rod, which afterward becomes a long filament traversing the elongated middle-piece and terminating in front in an end-knob at the base of the nucleus, while the ring lies at its posterior limit. The idiozome (a true attraction- sphere) degenerates without taking part in the formation of an aero-. 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 Wilson, Edmund B. (Edmund Beecher), 1856-1939. New York, Macmillan
Size: 1792px × 1395px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectcells, bookyear1911
