. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 248 K. R. PORTER population of androgenetic R. pipiens haploids raised at a temperature of 20° C. It should not be concluded from these results that androgenetic frog embryos are incapable of further development than that expressed by a 10 or 12-day-old animal raised at 20° C. It is certainly true that the vast majority never go beyond this stage, but the occasional animal will continue longer and while showing abnormalities and a slower rate of growth, it will nevertheless take food and live over several weeks or months. Tw
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 248 K. R. PORTER population of androgenetic R. pipiens haploids raised at a temperature of 20° C. It should not be concluded from these results that androgenetic frog embryos are incapable of further development than that expressed by a 10 or 12-day-old animal raised at 20° C. It is certainly true that the vast majority never go beyond this stage, but the occasional animal will continue longer and while showing abnormalities and a slower rate of growth, it will nevertheless take food and live over several weeks or months. Two animals of the group described in Fig. 34 lived for five weeks and another, which developed from an. 1- 6 8 10 II AGE. IN DAYS 8 10 IN DAYS 16 - 24 FIG. 33. Graph depicting survival of population of 40 androgenetic haploids which were fixed when it was judged that they could not survive many hours. FIG. 34. Graph depicting survival of 3 different populations of androgenetic haploids which were allowed to die of natural causes. operated egg in more recent experiments, lived for sixteen weeks. It developed into a sizeable tadpole with small hind limbs. Cyto- logical examination of the tail epidermis has revealed that it was pre- dominantly haploid. The uniformity of a group of androgenetic embryos cannot, un- fortunately, be measured by any known unit but must be left entirely to the judgment of the investigator. The fact that the majority of the animals live for eight days, suggests that early development is quite normal and uniform from animal to animal. If, on the other hand, a few animals had died each day and in all stages from cleavage to tadpole, the development could be referred to as un-uniform. The. 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 Marine Biological Laboratory (Woods Hole, Mass. );
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
