TAILLESS BATRACHIANS 211 



with which it otherwise agrees, by the entire absence of 

 teeth. 



Dendrobates, of Tropical America, is an arboreal genus 

 made up of seven species, all of which are of small size. 

 The pupil is horizontal. The tympanum is more or less 

 distinct. The fingers and toes, the tips of which are 

 dilated into round, adhesive discs, are free. 



D. trivittatus, of Brazil and Peru, spawns in shallow 

 puddles in which the water evaporates within a few days. 

 When the water dries up, the father, who keeps a strict 

 watch over his offspring, transports the tadpoles to other 

 pools, the latter adhering to their parent's back by means 

 of their sucker-like lips. In this manner they are conveyed 

 from one pool to another, until the entire metamorphosis 

 has been completed. 



D. tinctorius secretes a very active poison, which is used, 

 not only as mentioned in the Introduction, for the poison- 

 ing of arrows, but also, it has been stated, for dyeing 

 green Amazon parrots, some of the green feathers of the 

 latter being plucked out and the bare places rubbed with 

 the living frog, with the result that the new feathers 

 appear as yellow instead of green. 



The family Engystomatid^ is composed of a large 

 number of mostly narrow-mouthed, ant-eating frogs or 

 toads ; it includes terrestrial, aquatic, and burrowing 

 types ; the latter have either the hind pair of limbs or 

 the front pair much strengthened, and provided with large 

 horny sheaths. The jaws are toothless. The transverse 

 processes of the sacral vertebra are dilated. 



Rhinoderma, represented by a single species, R. darzvinii^ 

 a small frog discovered by Darwin on his voyage in the 



