•04 



HARDWICK&S SCIENCE-GOSSIP. 



British) which is ahead of the sparrow ; it constructs 

 a domed nest with two chambers, one for the eggs, 

 and one for the male to roost in. If our sparrow 

 could be informed of this it would probably take the 

 hint. A little parlour would be very useful for the 

 male to sleep in during the cold nights, or to take 

 shelter in during a thunderstorm. 



Some philosophers maintain that there is no im- 

 provement in the habits of birds, man alone being 

 progressive. It must, however, be admitted that 

 there can be alteration, and if the alteration is for the 

 benefit of the species it must be an improvement. 



THE TREE TOAD and WOOD FROG {HYLA 

 VERSICOLOR and RANA SYLVAT1CA). 



By Dr. C. C. Abbott. 



A PRETTY batrachian, with which Americans 

 are more or less familiar, unless their whole 

 lives have been spent in a large city, is the tree-toad. 

 Unlike the common toad, which is terrestrial, or the 

 frogs that are aquatic, this animal leads an arboreal 

 life. In anatomical structure, therefore, it differs 

 from both the others, so far as this is necessary to its 



- ■' /y 



Fig. 124. — The Tree Toad (_Hyla versicolor). 



The so-called accidental variations which have often 

 been observed in the architecture of birds — many 

 showing a tendency to improved construction — would, 

 if properly investigated, be found not to be accidental 

 at all, but the result of a fixed law, of which we know 

 nothing. The probable fact is that birds progress 

 and decline like the various races of man, but the 

 steps are so slight and the process of progression so 

 slow, and the data by which we might judge so 

 limited, that we have not yet been able to take 

 adequate notice of any progression or improvement. 



{To be continued.) 



peculiar mode of life ; the most prominent variation 

 being found in the fingers and toes, which] are more 

 or less dilated into disks at their tips. 



This little tree-toad soon attracted the attention of 

 the early colonists of New Jersey, and I find mention 

 made of it as early as 169S. Gabriel Thomas refers 

 to a "sort of Frog that crawls up to the tops of trees, 

 there seeming to imitate the Notes of several birds." 

 The idea of the resemblance of its note to that of 

 " several birds," or of any one kind of bird, is rather 

 amusing. 



Like all of our batrachians, the tree-toads make 

 their way to the water, as the proper place for de- 



