A SUMMER TRIP. 75 



cipient varieties, which may possibly establish them- 

 selves as species in the course of time. But in our 

 smaller outlying islands, with their equable temperature 

 and very insular character, including generally the 

 absence of many common enemies such as birds of 

 prey, foxes, weasels, and so forth numbers of separate 

 local s'pecies have been noted by Mr. Wallace and other 

 investigators. Thus, Shetland and the Isle of Wight 

 have each a peculiar beetle of their own ; Man has a 

 dwarf butterfly and a tailless cat ; Guernsey has a caddis- 

 ily all to itself ; and the Kerry Mountains (almost insular 

 in climate and abounding in peculiar plants of southern 

 type) have a water-snail. Almost every little island has 

 also numerous local varieties. These cases are quite 

 different from that of the Steep Holm peony, which is 

 merely a flower belonging to the great chain from the 

 Caucasus to the Pyrenees, reappearing in an isolated 

 spot in Britain ; whereas the peculiar island animals are 

 confined to these small areas, on which therefore they 

 have presumably been developed. Furthermore, lakes 

 are to the world of water what islands are to the world 

 of land ; and Dr. Giinther has shown that almost every 

 mountain tarn in Scotland, Ireland, and the Orkneys has 

 its own peculiar species of trout or charr. Putting all 

 these things together, then, it seems very probable that 

 the two Lundy beetles have really been developed on 

 the island itself from ancestral forms similar to those of 

 England, but specially selected under the particular 

 circumstances of the locality in which their lot was cast. 

 If all the outlying eyots of Kerry, Connemara, and the 

 Hebrides were equally well searched, it is extremely 

 likely that dozens more and similar cases of insular 

 species would be discovered without much difficulty. 



