Text-book of comparative anatomy . nal feet.—The cephalothoracicshield has developed greatly, its lateral parts project freely as rudimentary branchio-stegites. Stage K then follows, with developed eye-pigment and the rudiments of the the young Crustacean, which is already tolerably similar in appearance to-the adult, is hatched from the egg. The fusing of the anterior thoracic ganglia toform the infra-cesophageal ganglion has begun. The forked telson has become around plate, and the abdomen resembles that of the adult. The liver is formedalmost exclusively by processes of fold
Text-book of comparative anatomy . nal feet.—The cephalothoracicshield has developed greatly, its lateral parts project freely as rudimentary branchio-stegites. Stage K then follows, with developed eye-pigment and the rudiments of the the young Crustacean, which is already tolerably similar in appearance to-the adult, is hatched from the egg. The fusing of the anterior thoracic ganglia toform the infra-cesophageal ganglion has begun. The forked telson has become around plate, and the abdomen resembles that of the adult. The liver is formedalmost exclusively by processes of folding of the wall of the mid-gut ((/. Figs. 274and 280). FIGS. 275-280.—Astacus fluviatilis. Median longitudinal sections through embryos atdifferent stages of development. In Figs. 275, 276, 277, and 279 only the ventral side of theembryo is depicted, in Figs. 27S and 280 the whole embryo in longitudinal section. In Fig. 280 theposition of the embryo is the reverse of what it is in the other figures (all Figs, after Reichenbach. FIG. 275.—Stage C. TA, Thoraco-abdominal rudiments ; ene, eudodermal invagiiiatiou (gastrulainvagination); m, mesodenu ; hi, cephalic lobes.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectanatomycomparative
