172 THE COURTSHIP OF ANIMALS 



with such of the Newts where there is no amorous display 

 before embrace, is significant. 



And now, as touching the musical performances of 

 these troubadours. These commence in the early spring. 

 With many species, as with our Common Frog (Rana 

 Umporaria), nothing more than loud croakings are attained. 

 But with others this " music " is enormously increased in 

 volume by resonators in the form of air-sacs or wind- 

 bags. We may surely, with some show of certainty, 

 liken this " music " to the song of birds, and assign its 

 primary purpose to the same cause — a device to advertise 

 their presence to wandering females seeking mates. That 

 birds sing after mates have been found, and later, is no 

 doubt due to a general feeling of " fitness," which finds 

 expression in what has become the usual mode for such 

 emotional states. Most people must have heard the spring 

 concerts of our Common Frog ; but these are incomparably 

 surpassed in volume by the Edible Frog and the Bull 

 Frog, which are provided with large, globular, inflatable, 

 air-sacs in the throat, serving as voice-resonators. Such 

 performances, however, are mere bawlings compared 

 with some other species, which mew like cats, or bark 

 like dogs. The most famous of all is the Brazilian 

 " Ferreiro " or " Smith " {Hylodes Jaber), whose voice is 

 one of the most characteristic sounds to be heard in 

 Tropical South America. ** Fancy," says Dr. Gadow, 

 " the noise of a mallet, slowly and regularly beaten 

 upon a copper plate, and you will have a pretty good 

 idea of the concert given generally by several individuals 

 at the same time and with slight variations of tone and 

 intensity." When seized, the performer utters a " loud 

 and shrill, most startling cry, somewhat similar to that 

 of a wounded cat." Another, a Paraguayan species, 



