92 DR. EMIL A. GOELDI ON THE BREEDIIfG-HABITS [Feb. 5, 



the erection of the nest or pool, in a perfectly passive manner 

 however, that is sitting on the back of the female. However, his 

 erotic ardour is by no meaus such a frantic one as I have often 

 witnessed in certain European frogs and toads, for, if frightened, 

 the male jumps off and dives down, though not very far. Some 

 time after you will see him emerge again at a few feet distance, 

 and, if all danger seems past, he will suddenly climb up the 

 wall of his home and resume his former position. The building 

 operations are performed in the most absolute silence. The 

 croakers around are all males clamouring for a mate. 



These Tree-Frogs work exclusively during the night ; in the 

 daytime no sign of Batrachian life can be detected about the 

 pools. 



Pool no. 3 was finished in two nights (18th and 19th February). 

 On the 20th, in the morning, it was filled with eggs. But on 

 other pools we observed that the eggs sometimes appear only 4 or 

 5 days after their completion. From 4 to 5 days is necessary for 

 the young tadpoles to leave the eggs ; various circumstances, 

 especially the weather, cause sensible differences. Heavy rain- 

 fall may destroy the pools, rapidly reducing the height of the 

 walls and thus prematurely releasing part of the tadpoles. But 

 a good number of them will be left on the bottom, and will 

 abandon their nursery only in due time. The parents keep 

 during the day in the neighbourhood of their pools, but are very 

 difficult to discover ; sometimes we detected the female hidden at 

 the bottom of the pool. 



Eggs and tadpoles were carefully studied, observed, and com- 

 pared, in order to get a positive and sure basis for an accurate 

 determination and to avoid any chance of confusion. My cousin 

 undertook to rear simultaneously tadpoles in unlimited freedom 

 and others kept in tubs, some specimens being put into alcohol 

 from time to time, carefully noting the results. Details about 

 dimensions, coloration, and changes with growth, I reserve for 

 a future note. I may, howevei', anticipate this by stating that 

 the tadpoles of Hyla faher, though rapidly attaining a large size, 

 as may be expected of one of the largest species of Tree-Frogs, 

 preserve for a long time the larval tail, Mhich disappears only 

 when the young frog has reached nearly 3 cm. in length. A 

 young " ferreiro " of these dimensions, which had just lost its 

 tail, was sent by me some months ago to Mr. Boulenger for 

 the British Museum collection. 



Having seen several hundreds of adidt individuals alive, I may be 

 allowed to say a few words as to the external features of Hyla 

 faher. To define what is in fact to be considered as the normal 

 coloration is by no means an easy task, as all the Brazilian Tree- 

 Frogs I have yet observed modify their colours wonderfully 

 according to the surroundings and especially the different degrees 

 of light. Put one of these Hyla faher near the windo\\', in a well- 

 illuminated place, it will rapidly turn pale ; examine the same 

 individual at night, and the longitudinal median stripe of the 



