. Studies in general physiology. Physiology; Phototropism; Geotropism; Reproduction; Irritability; Regeneration (Biology). cells at the periphery the blastoderm becomes smaller (Fig. 110). At 6: 35 o'clock the liquefaction of the cells at the periphery had progressed much farther (Fig. 111). The diameter of the blastoderm was only a little more than three- fifths of the diameter the egg possessed four hours earlier when it was in the sixty-four-cell stage. Around the blastoderm lay granular masses, which were in all probability the remains of the lique- fied cells. Soon thereafter a change (sh
. Studies in general physiology. Physiology; Phototropism; Geotropism; Reproduction; Irritability; Regeneration (Biology). cells at the periphery the blastoderm becomes smaller (Fig. 110). At 6: 35 o'clock the liquefaction of the cells at the periphery had progressed much farther (Fig. 111). The diameter of the blastoderm was only a little more than three- fifths of the diameter the egg possessed four hours earlier when it was in the sixty-four-cell stage. Around the blastoderm lay granular masses, which were in all probability the remains of the lique- fied cells. Soon thereafter a change (shrinking?) occurred in the yolk, which served to close the experiment. The disappearance of the cleavage- FIG. no cells occurs more slowly therefore in the later stages of development than in the earlier stages of development. It may be of interest to raise the question: In what do these peculiar structural changes consist which lead to the fusion of the cleavage-cells in the absence of oxygen? If we wish to answer this question, we must acquaint ourselves more fully with the history and the significance of those peculiar refractive substances which appear in droplets. Soon after fertilization, before the union of the pro-nuclei, one observes in the center and upon the surface of the germ the appearance of several strongly refractive droplets. These undergo, as has already been said, a series of changes, of which the most remarkable is this, that shortly before the first cleavage a single system ^KJ- m of radiations coming from a common center is formed, which looks very much like the radiations about a centrosome. These radiations might be a process of emulsion, for the radii break up very rapidly into small droplets which are strongly. Digitized by Microsoft®. 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 work.
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