. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Adults Sept-Nov. Immotures Immotures Nov. -Jon Adults Adults Jon-Mor Immotures Moy-July Adults July-Sept Adults Exp. NO Aug -Oct. Adults 10 FIGURE 1. Testis weights demonstrating the seasonal gradient in testicular response to exposure to long photoperiods. The terminal horizontal bars indicate the range in sample weights, the middle horizontal bar indicates the sample mean and the solid rectangle represents the standard deviation plotted on both sides of the mean. N. D. = exposure to natural d
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Adults Sept-Nov. Immotures Immotures Nov. -Jon Adults Adults Jon-Mor Immotures Moy-July Adults July-Sept Adults Exp. NO Aug -Oct. Adults 10 FIGURE 1. Testis weights demonstrating the seasonal gradient in testicular response to exposure to long photoperiods. The terminal horizontal bars indicate the range in sample weights, the middle horizontal bar indicates the sample mean and the solid rectangle represents the standard deviation plotted on both sides of the mean. N. D. = exposure to natural day- lengths ; L = hours of artificial light per 24 hours. (end of Stage VI). By the end of the experiment, animals in the wild had initiated spermatogonial mitoses but their accessory sex organs were still atrophic (Stage I). The 18L sample underwent a highly significant increase in testis weight (Fig. 1) although two apparently healthy animals did not respond to the light treatment. Control animals retained small gonads that averaged significantly less in weight than those of wild animals in November (Fig. 2). Seminiferous tubule diameters were greater and spermatogenesis more advanced in the experi- mental sample (Table II). Whereas none of the control animals advanced further than spermatogenic Stage I, four of the experimentals were classified as early Stage III. The total cell number, however, was about half that present in a normal Stage III gonad. The accessory sex organs were partially stimulated by exposure to 18-hour day-lengths at this season (Table II). The ductus epididymidis underwent a very significant increase in diameter and epithelial height, in half of the sample the cells contained secretion granules (Stages II and III) ; in six animals sperm were present in the lumen (beginning of Stage III). Secretion granules and sperm were lacking in all the controls (Stage I). Neither the average of epithelial height nor diameter of the ductus deferens significantly inc
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
