. Chemical embryology. Embryology. 636 THE RESPIRATION AND [PT. Ill cmm. O2 or CO2 Warburg did not draw any conclusion from this finding, but it has acquired importance in view of subsequent researches on the nature of the substances combusted as energy sources during em- bryonic development. It will be again referred to in the section on the energy relations of the growing embryo. The figures given above demon- strated that weight for weight the spermatozoon was respiring more intensely than the egg-cell. When, however, the relations between the respiration of one spermatozoon and one egg-cel
. Chemical embryology. Embryology. 636 THE RESPIRATION AND [PT. Ill cmm. O2 or CO2 Warburg did not draw any conclusion from this finding, but it has acquired importance in view of subsequent researches on the nature of the substances combusted as energy sources during em- bryonic development. It will be again referred to in the section on the energy relations of the growing embryo. The figures given above demon- strated that weight for weight the spermatozoon was respiring more intensely than the egg-cell. When, however, the relations between the respiration of one spermatozoon and one egg-cell were compared, it was found that spermatozoon : unfertilised egg was as i : 500, while spermato- zoon : fertilised egg was as i : 3500. Another interesting calculation which Warburg made from his experimental data was that only 0-0045 mgm. of spermatozoon nitrogen were required to fertilise 7 to 8 mgm. of egg nitrogen, to fertilise i mgm. of egg nitrogen TsW to 20W mgm. spermatozoon nitro- gen were necessary. One conclusion from all this was that, as far as respira- tion experiments were concerned, it was unnecessary to make much cor- rection for the spermatozoal respira- tion, owing to its extreme smallness. The next step forward was taken by Shearer, who in 1922, by using a special form of the Barcroft differential manometer, was able to carry out the fertilisation of Echinus microtuberculatus eggs actually inside the closed chamber of the apparatus, and observe more intimately still the earliest stages of the embryonic respiration. Fig. 109, taken from Shearer's paper, shows the phenomena which may under such conditions be observed during the first 10 minutes, during the period which elapsed between fertilisation and the. 5 minutes Fig. 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 Nee
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Keywords: ., bookcentury1900, bookpublishernewyorkthem, booksubjectembryology
