. The American journal of anatomy. cellsseems to he identical so far as optical appearances are concerned withthat in the ^ligment layer. The nuclei, the staining and the general ap-pearance of these cells, aside from the pigment, indicate that they areother than the ordinary branched mesenchyme cells. As the buds con-tinue to grow the knob-like ends may send out liranches and elongate ormay remain spherical for a while, at least after the disappearance ofthe connecting pedicle between it and the pigment layer. In Fig. 1, from a chick 6 days and 13 hours old, is a I)ud \\\\\\ a nar-row pedicle
. The American journal of anatomy. cellsseems to he identical so far as optical appearances are concerned withthat in the ^ligment layer. The nuclei, the staining and the general ap-pearance of these cells, aside from the pigment, indicate that they areother than the ordinary branched mesenchyme cells. As the buds con-tinue to grow the knob-like ends may send out liranches and elongate ormay remain spherical for a while, at least after the disappearance ofthe connecting pedicle between it and the pigment layer. In Fig. 1, from a chick 6 days and 13 hours old, is a I)ud \\\\\\ a nar-row pedicle and enlarged distal end. The bud is clearly a prolongationof the outer or pigment layer of the optic cup from near the choroidfissure and projects into the cleft heap of condensed mesenchyme. Theenlarged distal end is to be found in the neighboring sections and consistsof several cells with nuclei. The yellow brown pigment granules ofsimilar character are present in the bud and in the pigment layer. This WiUTon Harnion Lewis 409. Fig. 4. From a chick 7 days, 22 hours 130 dia. P. C, wandering pigment cells. was tlie only bud foiiiul in the entire series of this eye and no wanderingpigmented cells were found. In Fig. -i the elongated epithelial budconsists of several cells with nucleiand pigment granules similar tothose in the pigment layer. Theloose pigment cells (Pc), seen inthis figure, are evidently derivativesof this bud, their position, size,L-haracter of the nuclei, protoplasmand pigment granules all indicatethis. The hud in this section is seento arise from a definite place on theconvex angle formed by the bendingof the epithelial layers into theciliary process. In this same eyethere are several other buds arising from similar locations at the angles where the epithelium bends intoother ciliary processes. At some of these places there are detachedmasses of pigmented epithelium, the pedicles probably having just brokenaway and left the distal end of the bnd in po
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectanatomy, bookyear1901
