. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE DEVELOPMENT OF FASCIOLAKIA. 15! With the aid of such evidence as I have been able to obtain, and Osborn's interesting discovery ('04) of amitosis in the endo- derm, I think I may formulate a scheme to account for the transfer of materials which probably takes place. Osborn ('04) announced that he had discovered amitosis in the endoderm of the gastrula^ of Fasciolnria and associated, very justly, I think, these nuclear phenomena with digestion. I have been able to verify these results, not, however, until I had been thoro
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE DEVELOPMENT OF FASCIOLAKIA. 15! With the aid of such evidence as I have been able to obtain, and Osborn's interesting discovery ('04) of amitosis in the endo- derm, I think I may formulate a scheme to account for the transfer of materials which probably takes place. Osborn ('04) announced that he had discovered amitosis in the endoderm of the gastrula^ of Fasciolnria and associated, very justly, I think, these nuclear phenomena with digestion. I have been able to verify these results, not, however, until I had been thoroughly led astray by the assertion that the nuclear divisions in question occur in the gastrula stage. All my earlier larvae show no signs either of the " cuboidal endoderm" or of the amitoses of which Osborn speaks. The latter phenomenon I finally discovered in a larva that had a velum, and was therefore well past the period of cannibalism. Fig. 8 is compounded from several sections ob- vei op FIG. 8. Composite figure made up from several adjacent sections oblique to the antero-posterior axis. The external kidneys, not yet subvelar in position, are cut horizontally. Opsp., optic cup. vel., velum. The arrows are intended to indicate the probable paths of waste products reaching the exterior from the digestive tract ? obj. 3 oc. seen in transverse section, via the external kidneys. Leitz lique to the antero-posterior axis of this larva. The oesophagus is cut transversely and the cells which compose it are dorsally, large, polynucleated, and highly granular, with vacuoles at their distal ends. The nuclei appear to have arisen amitotically. Some of these cells have burst and their contents may be seen oozing out. They bear a striking resemblance to the cells of the external kidneys. The cells of the lateral and ventral walls of the cesophagus have a very different appearance. These, instead of being long. Please note that these images are extracted from scanned page
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
