. Journal of morphology. eful studyof both surface views and serial sections I have come to the con-clusion that the differences in the grooves appearing early andlate in the median line of the neural plate of Cryptobranchusare differences in degree, not in kind, hence I have used the termneural groove throughout. In living material the embryo may be viewed by transmittedlight. During the early part of this stage (figs. 146 and 147) 502 BERTRAM G. SMITH the broad lateral bands lying in the posterior part of the egg atsome distance from the median line are more marked than inthe preceding stage
. Journal of morphology. eful studyof both surface views and serial sections I have come to the con-clusion that the differences in the grooves appearing early andlate in the median line of the neural plate of Cryptobranchusare differences in degree, not in kind, hence I have used the termneural groove throughout. In living material the embryo may be viewed by transmittedlight. During the early part of this stage (figs. 146 and 147) 502 BERTRAM G. SMITH the broad lateral bands lying in the posterior part of the egg atsome distance from the median line are more marked than inthe preceding stage. The study of sections shows that they aredue to the combined optical effect of the mesoderm and anunusually thick region of the entoderm. The neural groove is par-ticularly translucent. The greatly reduced blastocoele persistsin the region of the equator on the antero-ventral side of the egg;the center of its external wall is marked by a pit, the vestige ofthe fenestra. During the latter part of Stage 12 (fig. 148) the.
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Keywords: ., bookcentury1900, bookdecade1, booksubjectphysiology, bookyear1912
