INTRODUCTION. 29 



establish a species in any new locality. Frequently 

 it happens that the species seems to be on the increase 

 at first, but then there is a decline, and after a few 

 years the new plantation has entirely vanished. In 

 other cases, the species disappears immediately after 

 the introduction takes place, or lingers on for many 

 years if it receives special and uninterrupted pro- 

 tection. 



It may not be generally known that the English 

 Hare {Lepus Europeans) is not found in Ireland, where 

 the Mountain Hare (Lepus variabilis) alone occurs. 

 Attempts to acclimatise the English species have 

 been made in a number of places in Ireland, but 

 many of them have been failures, and not one of 

 them has been a signal success. 1 Similarly, the 

 endeavour to introduce the French or Red-legged 

 Partridge (Caccabis rufd) into Ireland has met with a 

 like result. According to Dr. Day, it was tried during 

 the summer of 1869 to naturalise the Sterlet (Acipenser 

 ruthenus) from Russian waters into the Duke of 

 Sutherland's River Fleet by importing artificially im- 

 pregnated ova. From one hundred and fifty to two 

 hundred lively young sterlets are said to have been 

 turned out, but nevertheless the experiment met with 

 no success. Several fortunately abortive efforts were 

 also made in British rivers to establish Silurus glanis, 

 a hideous monster of a fish, and quite unpalatable. 



1 I might refer any one more specially interested in these intro- 

 ductions to an article on this subject in the Irish Naturalist of March 

 1898, by Mr. Barrett- Hamilton. 



