. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DERMAL PLIC;E FORMATION is Stage 2. Lame in Early Stage of Metamorphosis.—The visible ex- ternal metamorphic changes of the larva include growth of the hind- limbs and slight atrophy of the tail. Otherwise, the larva is still tad- pole-like in most respects. Externally, the dermal plicae are indicated by broad, indistinct bands of a grayish coloration. Histologically, the epidermis is unchanged in thickness but appears to be less pigmented. The stratum spongiosum is considerably thickened to accommodate the glands. The poiso
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DERMAL PLIC;E FORMATION is Stage 2. Lame in Early Stage of Metamorphosis.—The visible ex- ternal metamorphic changes of the larva include growth of the hind- limbs and slight atrophy of the tail. Otherwise, the larva is still tad- pole-like in most respects. Externally, the dermal plicae are indicated by broad, indistinct bands of a grayish coloration. Histologically, the epidermis is unchanged in thickness but appears to be less pigmented. The stratum spongiosum is considerably thickened to accommodate the glands. The poison glands are fairly well developed and of a good size. The muscular and fibrous layers of the latter are present. Prac- tically all have ducts developed. The inner epithelial layer is composed of cuboidal-shaped cells, while large granules occupy the central cavity of the gland. The glands are definitely poison glands. Small mucous glands are also found, some of which have acquired ducts. In addition, glandular " nests " are also found in the usual location, the inference being that they are developing mucous glands. The adjacent back in- tegument now possesses a few, widely scattered gland " nests," which appear smaller than those described in Stage 1 dermal plicae. Stage 3. Larva near End of Metamorphosis.—The animals are typi- cally frog-like, although the tympanic membranes are not as yet fully developed. The tail has atrophied to a small stump. The dermal plicae appear narrower, distinctly marked off from the adjacent integument and grayish-white in color. Histologically, the epidermis has thickened and contains more layers than that of the adjacent back integument. The stratum spongiosum is especially thickened, while the melanophores in this layer and the epidermis appear to be considerably less evident. The integument as seen in cross-section is markedly convex along its epidermal surface. The glands are much larger than hitherto described. The p
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
