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less secretive in habit than the salamanders and therefore 

 much better known. The frog has played a part in connection 

 with some great discoveries, notably that of galvanism through 

 Galvani observing the twitching of the muscles of a frog's hind 

 limbs when these were suspended by copper wires which came 

 into contact with iron. The frog and the chick have been 

 employed as good typical examples of vertebrates in the prep- 

 aration of works on anatomy, histology and embryology. The 

 frog's foot is so frequently used to show the circulation of the 

 blood that dealers in microscopes make a ' ' frog-plate ' ' espe- 

 cially for this purpose. In literature the toad has been men- 

 tioned as being venomous and possessed of occult powers. It 

 was long believed capable of producing warts. On account of 

 its insect-destroying propensities, it is now commonly recog- 

 nized as one of man's best friends in the field and garden. 



As ponds and ditches have been drained, the aquatic forms 

 have removed to greater distances from human dwellings, and 

 only the more terrestrial toad and the arboreal tree-frogs have 

 remained. All of our species have been described, but I think 

 the first mention of the cricket frog being found in this region 

 was made in my paper upon salamanders, read before this 

 Society in 1895. 



The breeding habits of these animals vary, but all lay their 

 eggs in water or moist places. 



The purety amphibious and really aquatic species are three. 

 Of the other eight, one is burrowing, five tend to be terres- 

 trial, inhabiting the woods and fields and two are arboreal. 

 The times and places of breeding, as well as the period of met- 

 amorphosis will be mentioned under specific headings. 



The frog tadpole ("pollywog") is believed to repeat the 

 history of a fish-like ancestor. Its habits, its mode of breathing, 

 even the arrangement of its blood-vessels and many structural 

 details, are those of fishes. One of the theories of evolution 

 is that during development each animal tends to repeat in 

 some degree the history of its ancestors, and that the later in 

 life variation took place in them, the later in embryonic life 

 would we find the disused structures persisting. Per contra, 

 the earliest phases of development must repeat that of the 



