. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. KTHEL GLANCY D'ANGELO both of the isolated gland and of glands within the intact For this purpose the observations were made with a Leitz apochromatic oil objective and a triple lens condenser. The equipment was sufficient to resolve the hexagonal aper- tures of the Pleurosignia angulatum. The distinct and sharply defined bands were beaded in some regions, and homogeneous in appearance in others. The interband regions, which were much less refractile, generally appeared either homogeneous or finely granular
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. KTHEL GLANCY D'ANGELO both of the isolated gland and of glands within the intact For this purpose the observations were made with a Leitz apochromatic oil objective and a triple lens condenser. The equipment was sufficient to resolve the hexagonal aper- tures of the Pleurosignia angulatum. The distinct and sharply defined bands were beaded in some regions, and homogeneous in appearance in others. The interband regions, which were much less refractile, generally appeared either homogeneous or finely granular. In unusually large chromosomes the granulation was coarse and often the arrangement gave the effect of longitudinal striations. These granular striations, which were seen at all levels in the chromosomes, were individually con- nected to the beads in the bands. During these observations the chromosomes were not under tension and in the case of the isolated gland were free from compression. That the salivary gland chromosome is made up of numerous longitudinal fibrils was further indicated by microdissection. The chromosome membrane was first removed by a very fine microneedle over a length of several bands from the region to be studied. The needle was then inserted into the margin of an exposed inter- band region. This adhered to the needle and, when the needle was carefully moved to one side, a strip of very thin fibril with one end on the tip of the needle could be seen being carried away from the chromosome. As the fibril was being carried still farther it was separated from the chromosome over a length of several bands (Fig. 4).. FIGURE 4. A single fibril with a chromoneina-like appearance being removed by a microneedle from a chromosome within the intact cell. The isolated fibril showed nodular swellings which corresponded in position with the bands from which it was being separated. This was done over and over again with the same chromosome and with different chromosome
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
