. The Biological bulletin. Biology; Zoology; Marine biology. 354 WILLIAM H. TELFER AND L. DAVID RUTBERG The volume of an oocyte was calculated from measurements of its linear dimensions. The shape of a growing oocyte approximates an ellipsoid with two equal axes. The disparate axis is the longitudinal one, or that which coincides with the axis of the tubular ovariole (Figs. 1 and 2). Although the nurse cells accompanying each oocyte tend to flatten its anterior end (Fig. 2) and thus cause some deviation from the shape of an ellipsoid, this effect is progressively reduced as the oocyte enlarges
. The Biological bulletin. Biology; Zoology; Marine biology. 354 WILLIAM H. TELFER AND L. DAVID RUTBERG The volume of an oocyte was calculated from measurements of its linear dimensions. The shape of a growing oocyte approximates an ellipsoid with two equal axes. The disparate axis is the longitudinal one, or that which coincides with the axis of the tubular ovariole (Figs. 1 and 2). Although the nurse cells accompanying each oocyte tend to flatten its anterior end (Fig. 2) and thus cause some deviation from the shape of an ellipsoid, this effect is progressively reduced as the oocyte enlarges and is undetectable during the last three-quarters of the volume increase. Therefore, the volume of a growing oocyte could be estimated by measuring its longitudinal and transverse diameters with a filar micrometer and by solving the appropriate equation for the volume of an Figure 1. An ovariole dissected from a female Cecropia on the seventeenth day of its transformation from a pupa into a moth. The individual oocytes lie in sequence with the largest at the posterior end of the ovariole. Small fragments of fat body adhere to the outer wall of the ovariole. Figure 2. Several oocytes which were removed from the ovariole shown in Figure 1. The five nurse cells form a transparent cap at the anterior end of the smaller oocytes. At the lower left is an oocyte which is nearing maturity. Magnification, 20 X. The most convenient index to the size of the mature oocyte was its weight, as determined with a semi-micro balance. Weighing was possible in this case because the rigid and comparatively impervious chorion allows the egg to be blotted and weighed without the loss of significant quantities of water from the oocyte itself. As in the case of the growing oocyte, the volume of a mature oocyte could also be calculated from measurements of its diameters. The shape of the mature oocyte differs from that of the growing oocyte in that its two transverse diameters. Please note
Size: 1957px × 1277px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectb, booksubjectzoology
