SUB-FAM. 3. DENDROBATINAE.–About one dozen arboreal little frogs have been separated from the Raninae proper on account of the entire absence of teeth. This mere loss of teeth, and the geographical distribution suggest that these frogs do not form a natural group, but have been developed independently from other Ranidae, the Neotropical _Dendrobates_ from some likewise Neotropical genus like _Prostherapis_, the Malagasy _Mantella_ from an African form like _Megalixalus_. The sacral diapophyses are cylindrical. The omo- and meta-sternum are well developed. The fingers and toes are free, their terminal phalanges are T-shaped and carry regular, round, adhesive discs. The tympanum is distinct, although sometimes, in _Dendrobates_, very small. The pupil is horizontal. _Dendrobates._–The tongue is elongate, entire and free behind. The omosternum has a weak, semi-ossified style, but the metasternum remains cartilaginous. The males have a subgular vocal sac. Seven closely-allied species inhabit tropical America. _D. tinctorius._–This pretty little species, scarcely 1½ inch in length, is quite smooth, varies much in coloration, and forms local races to a certain extent. Some are quite black, others are grey above, black on the sides and under parts; or they are grey with large black patches. A fourth variety is black above with several white or pink longitudinal stripes, while the under parts are grey, spotted with black. In others, again, the ground-colour is black, with white stripes and spots above, marbled below. But this enumeration does not exhaust the list, since living specimens are sometimes much more conspicuously coloured, some being black with large patches of saturated yellow on the head and back, while the limbs are orange red and black. This species has a wide range, from Panama to Ecuador and to the mouth of the Amazon. It owes its specific name to the peculiar use made by man of the strongly poisonous secretion of the tiny glands of the otherwise smooth skin. Other species are doubtless employed in the same way. The poison is mainly used for "dyeing" the green Amazon-parrots. This is done as follows:–The green and blue feathers on the head and neck, or other parts, according to the fancy of the {273}operator, are plucked out, and these places are rubbed with the poison, often simply with the living frog, certainly not with its blood, as is sometimes asserted. This operation may be repeated when the new, young feathers begin to bud. The result is that these appear yellow instead of green, and since the Brazilians, and to a certain extent the Portuguese, are rather partial to these artificially-produced freaks or "contrafeitos" as they call them, the industry is kept up. That the poison is also used for arrows has been mentioned on p. 38. [Illustration: FIG. 53.–_Dendrobates tinctorius_, three colour-variations. × 1.]