. Journal of morphology. ecturus in this stage seems to show aneven stronger tendency toward the meroblastic condition. Butthis is merely a consequence of the tendency for the third cleavagefurrows to come in obliquely or latitudinally; a comparison oflater stages shows that the meroblastic tendency is in reality atrifle less strongly expressed in Necturus (figs. 107 and 108) thanin Cryptobranchus. In Amia (Dean 96; Whitman and Eycleshymer 97) the fifthcleavage furrows appear in two sets: an outer set cutting theeight macromeres latitudinally; and an inner set cutting thefour micromeres in a h
. Journal of morphology. ecturus in this stage seems to show aneven stronger tendency toward the meroblastic condition. Butthis is merely a consequence of the tendency for the third cleavagefurrows to come in obliquely or latitudinally; a comparison oflater stages shows that the meroblastic tendency is in reality atrifle less strongly expressed in Necturus (figs. 107 and 108) thanin Cryptobranchus. In Amia (Dean 96; Whitman and Eycleshymer 97) the fifthcleavage furrows appear in two sets: an outer set cutting theeight macromeres latitudinally; and an inner set cutting thefour micromeres in a horizontol plane, hence not visible fromthe surface. Stage 6: (figs. 97 to 102 and 212 to 214). This stage is charac-terized by the presence of the sixth cleavage furrow, giving amaximum of sixty-four cells, some of the macromeres being in-completely divided. Considerably more than half the cells aremicromeres; these occupy an area whose diameter extends overonly about 90° of the circumference of the egg. Hence the mero-. 97
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Keywords: ., bookcentury1900, bookdecade1, booksubjectphysiology, bookyear1912
