. Chemical embryology. Embryology. 1072 PROTEIN METABOLISM [PT. Ill © Protein in yolU '\ ^ " M yolk-sacs I O » „ liquid part >Rlddle ® » " solid central core j X " " inbracellularyolk). Days —I L—J \ \ L_J 15 16 17 18 19 20 21 Fig. 308. The subsequent fate of the ovomucoid fraction and the part played by it in metaboHsm have been discussed in Section 8, Here, however, it may be noted that the ovomucoid is not absorbed by the embryonic vessels at a different rate from the ovoalbu- men. This was demonstrated by By waters' experiments, a graph -g of which is given in Fig. 3
. Chemical embryology. Embryology. 1072 PROTEIN METABOLISM [PT. Ill © Protein in yolU '\ ^ " M yolk-sacs I O » „ liquid part >Rlddle ® » " solid central core j X " " inbracellularyolk). Days —I L—J \ \ L_J 15 16 17 18 19 20 21 Fig. 308. The subsequent fate of the ovomucoid fraction and the part played by it in metaboHsm have been discussed in Section 8, Here, however, it may be noted that the ovomucoid is not absorbed by the embryonic vessels at a different rate from the ovoalbu- men. This was demonstrated by By waters' experiments, a graph -g of which is given in Fig. 306. The S ratio of the coagulable to the "S uncoagulable protein nitrogen ^" remains the same throughout \ development, though in some •; cases Bywaters' points are rather » erratic, and there may well be 12° some interesting relations hidden under this approximation (see also Fig. 307). Other points also emerge from Table 135. Sznerovna's figures illustrate the transfer of nitrogen from yolk and white to embryo, the embryo having at the end about as much nitrogen as the yolk had at the beginning. Iljin's figures illustrate the large increase (perhaps due to ovomucoid) in the unpre- cipitable nitrogen of the yolk towards the end of development. But more illuminating are the figures of Riddle represented graphically in Fig. 308, for they show that, in per cent, of the dry solids in the yolk, the yolk- proteins rise during the last 5 or 6 days of incubation. This is due to a preference on the part of the embryo for lipoids and fats, ^'^' 3°9' the concentration of which correspondingly rapidly decreases, and the graph has only to be compared with that in Fig. 252, where the absorption intensity of the embryo at different times is given, to show how good the correlation is. For 5 or 6 days before hatching. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appeara
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Keywords: ., bookcentury1900, bookpublishernewyorkthem, booksubjectembryology
