. Brimleyana. Zoology; Ecology; Natural history. Necturus Testis and Reproduction 57 N. lewisi. The interlobular cells associated with the immature region of seminiferous lobules, or those surrounding lobules containing develop- ing germ cells appear, morphologically, to be undifferentiated (see Fig. 2). When, however, the lobules undergo spermiation this, in as yet an maturing lobules • medial zone caudal zone. ANNUAL REGROWTH tunic • all zones Fig. 2. Diagrammatic representation of N. maculosus testis towards the close of spermatogenetic activity. Seminiferous lobules (clear areas) containin
. Brimleyana. Zoology; Ecology; Natural history. Necturus Testis and Reproduction 57 N. lewisi. The interlobular cells associated with the immature region of seminiferous lobules, or those surrounding lobules containing develop- ing germ cells appear, morphologically, to be undifferentiated (see Fig. 2). When, however, the lobules undergo spermiation this, in as yet an maturing lobules • medial zone caudal zone. ANNUAL REGROWTH tunic • all zones Fig. 2. Diagrammatic representation of N. maculosus testis towards the close of spermatogenetic activity. Seminiferous lobules (clear areas) containing the germ- inal elements empty into the main, central, longitudinal collecting duct. Lobular portions adjacent (proximal) to this duct contain immature germ cells that act as a reservoir for successive bouts of spermatogenetic activity. Mature germ cell cysts are in lobular portions distal to the collecting duct. Lobules are sur- rounded by an interlobular tissue (grey areas), development of which depends upon the state of differentiation of the lobules. The kinetics of spermatogenesis are indicated by arrows showing the proximal to distal development of germ cells (annual regrowth) and the caudocephalic differentiation of germ cells that occurs in distal portions of the lobules and their associated interlobular tissue during the annual breeding season (maturational wave). From Pudney et al. (1983).. 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 North Carolina State Museum of Natural History. [Raleigh, NC : North Carolina State Museum of Natural History]
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Keywords: ., bookcentury1900, booksubjectnaturalhistory, booksubjectzoology
