. Chemical embryology. Embryology. 882 GENERAL METABOLISM [PT. Ill H Allanfcoic(Kamei) nAmniotic( ^ ) ® Allantoic (Rske&,Bqyden) & Riddle found that the fluid filling the subgerminal cavity in the pigeon's egg would hardly form a coagulum when heated, and evi- dently contained only a little protein. Closely associated with the water metabolism of the egg is the origin of the amniotic and allantoic liquids. Kamei has studied their increase in volume (see Fig. 227). The allantoic fluid shows at first a fairly regular rise and by the middle of development reaches 6 , after which it pro
. Chemical embryology. Embryology. 882 GENERAL METABOLISM [PT. Ill H Allanfcoic(Kamei) nAmniotic( ^ ) ® Allantoic (Rske&,Bqyden) & Riddle found that the fluid filling the subgerminal cavity in the pigeon's egg would hardly form a coagulum when heated, and evi- dently contained only a little protein. Closely associated with the water metabolism of the egg is the origin of the amniotic and allantoic liquids. Kamei has studied their increase in volume (see Fig. 227). The allantoic fluid shows at first a fairly regular rise and by the middle of development reaches 6 , after which it probably falls. These 6 represent about 15 per cent, of all the water in the egg, that per- centage has been required to assist in the excretion of from 7 mgm. (Fiske & Boyden) to 3I mgm. (Needham) of uric acid (seep. 1092). Thereabsorp- tion of water from the allantois must begin very soon after the mid-point of development, for by the 12th day its uric acid content is increasing while its volume is remaining steady or diminishing. The amniotic liquid, on the other hand, reaches what is practically its maximum by the loth day and does not fall until the final desiccation of the egg before hatching begins. The specific gravity of the amniotic liquid rises to a maximum on the 14th day but that of the allantoic liquid rises throughout development, as follows: Amniotic Allantoic 1-0062 1-0070 1-0630 1-0147 1-0400 1-0205 especially turtles, contain white^, and Agassiz gave a description of the histology of their yolk after laying, which has been interpreted by Bartelmez & Riddle as indicating 0) 2 E. Fig. 227. Day 9 17 The eggs of reptiles, ^ Deraniyagala describes the white as at first viscid and later quite mobile and limpid. This is precisely the opposite to what happens in avian eggs (see Figs. 207 and 215) but would be expected from the considerable water-intake (see p. 898, Table 105).. Please note that these images are extracted from scanned page images that
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