2 The Irish Naturalist. 



field, near Waterford, about the year 1630, and is noticed by 

 Colgan in a work printed in 1647." It appears, therefore, 

 that before the introduction of the Frog into Dublin, it already 

 existed in Waterford. 



Before further consideration of this evidence, a few remarks 

 on the Frog and its geographical range may not be out of 

 place. The Frog is certainly a most useful animal to man, 

 living as it does largely on slugs and insects destructive to 

 crops, but as it is often believed to be a fruit-eater it is 

 generally killed when found in strawberry-beds, which it 

 frequents in order to eat the small black slug, Arion hortensis, 

 which commits such ravages among the ripe fruit. 



All frogs which have been hitherto discovered in Ireland 

 are of the species known as the Common Frog {Rana tem- 

 poraria, Iv-), but in England the Kdible Frog {Ra?ia esculenta, 

 ly.), occurs also. One of the most characteristic features by 

 means of which these two species may be distinguished, is the 

 dark triangular patch behind the eye in the Common Frog. 

 This latter varies very considerably in colour, between grey, 

 yellowish, and light brown, and, as a rule, the male is darker 

 than the female. 



The Edible Frog has a limited distribution in the British 

 Isles, occurring only in some of the eastern counties of 

 England. The Common Frog, on the other hand, is found 

 all over England, Scotland, and Wales. Both species have a 

 very wide general distribution — the Edible Frog ranging into 

 Northern Africa, and from Eastern Europe, across Palestine 

 and Persia, into China and Japan. The more northern of the 

 two is certainly the Common Frog, and while it ascends the 

 Alps to a height of 9,000 feet,^ the Edible Frog is seldom 

 found higher than 3,000. This seems to indicate that the 

 former is able to resist greater extremes of temperature than 

 the other, but it may mean also that it is the more ancient 

 species of the two. 



It is generally acknowledged that many of the quick- 

 breeding mammals, and also some fishes, are easily intro- 

 duced artificially into districts which they have not previously 

 inhabited, provided that they find similar conditions to those 

 to which they are accustomed. But even in the case of verte- 

 brate animals, many resist artificial introduction, although the 



3 J. von Bedriaga, "Die Lurchfauna Kuropa's " (part I.), 1891. 



