. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VASCULAR BUDDING IN BOTRYLLUS 233 Nature of the blood-cells The blood-cells from which the inner vesicle originates are small, round cells. They show a strong affinity for thionin; further, they are more strongly stained by such vital stains as methylene blue (1/10,000 aq. sol.) or neutral red (1/10,000 aq. sol.) than other blood elements. In sections, it is seen that the cells have a hyaline cytoplasm; their nucleus is filled with a dense network of chromatin and lacks a nucleolus. The total picture suggests that they are c
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VASCULAR BUDDING IN BOTRYLLUS 233 Nature of the blood-cells The blood-cells from which the inner vesicle originates are small, round cells. They show a strong affinity for thionin; further, they are more strongly stained by such vital stains as methylene blue (1/10,000 aq. sol.) or neutral red (1/10,000 aq. sol.) than other blood elements. In sections, it is seen that the cells have a hyaline cytoplasm; their nucleus is filled with a dense network of chromatin and lacks a nucleolus. The total picture suggests that they are cells of a primitive nature. They are the lymphocytes in the terminology of Sabbadin (1955). Time of appearance The appearance of the vascular buds is limited to a certain phase in the life cycle of the colony. They appear only during a short period (about 10 hours), extending from later phase B to early phase C. At that time, the colony is at the maximum of its activity and, accordingly, the growth of the ampullae is also very active. In other phases, no buds are formed even where they are expected to appear. In phase D we sometimes find small buds; however, they are not new buds but older ones that have appeared in early phase C and are now on the way to dis- solution. Site of appearance In Botryllns colonies, numerous blood vessels traverse the test and terminate in contractile ampullae at the periphery of the colony; a flow of blood is maintained by them independently of heart action. The buds appear at the base of ampullae at a distance of about mm. from the tip (Fig. 10).. FIGURE 10. Vascular buds at the end of budding period. Note the various 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. ); Marine Biological Laboratory (Woods Hole, Mass.
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
