282 The Caribou 



could definitely be distinguished from those of 

 Greenland. The figures here given of the two 

 forms show how the antlers vary both between 

 individuals of the same species and of the two 

 species themselves, and the one is no greater 

 than the other. It is not improbable they cross 

 from the island to the mainland on the ice, 

 and vice versa, and a Greenland animal shot 

 among a herd of the Barren-Ground deer would 

 probably never exhibit any signs of his nativity 

 nor be considered as differing from the caribou 

 among which he was killed ; and the same may be 

 said of a mainland deer procured in Greenland. 

 Island forms that have become separated and 

 have no access to a continent as a rule will in 

 time develop characters that distinguish them 

 from their mainland ancestors ; but when com- 

 munication has not been entirely cut off, the 

 question naturally arises as to whether or not a 

 mingling of the two forms has not been continued, 

 even though at irregular intervals, and a produc- 

 tion of a distinct variety been delayed if not pre- 

 vented. In the present case more material is 

 needed of both species before any definite opinion 

 can be formed. At present they are difficult to 

 distinguish from each other by any of the char- 

 acters thus far produced. 



It may be well here, before proceeding to the 

 Woodland caribou, to consider for a moment the 



