. Journal of morphology. Fig. 148 Upper hemisphere of a living egg of Cryptobranchus allegheniensisviewed so far as possible by transmitted light, shortly before the appearance ofthe neural folds. X 9. It will be recalled that the dorsal lip of the blastopore firstappears, on the average, 68 degrees above the vegetal pole (), and that the ventral lip is first formed about 68 degreesfrom the vegetal pole on the opposite side (fig. 136). Hencethe dorsal and ventral lips are formed respectively at approxi-mately equal distances from the yegetal pole, though the ventra)lip is formed much la
. Journal of morphology. Fig. 148 Upper hemisphere of a living egg of Cryptobranchus allegheniensisviewed so far as possible by transmitted light, shortly before the appearance ofthe neural folds. X 9. It will be recalled that the dorsal lip of the blastopore firstappears, on the average, 68 degrees above the vegetal pole (), and that the ventral lip is first formed about 68 degreesfrom the vegetal pole on the opposite side (fig. 136). Hencethe dorsal and ventral lips are formed respectively at approxi-mately equal distances from the yegetal pole, though the ventra)lip is formed much later than the dorsal. We may now computethe amounts of overgrowth of the dorsal and the ventral lipsrespectively: at the close of Stage 12 the dorsal lip has overgrownthe yolk for an average distance of 55 degrees, and the ventrallip has advanced toward it through an arc of about 55 degrees; 504 BERTRAM G. SMITH. bip. yp-
Size: 1539px × 1624px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1, booksubjectphysiology, bookyear1912
