154 PAST AND PRESENT RANGE OF THE BEAR. [CH. Ill 



of disembarcation ; the further we recede from the coast 

 the rarer do the European Lumbricidse become; in the 

 interior of South America they are not to be seen. Prof. 

 Spencer met with exactly the same state of affairs in 

 Australia; the gardens in the towns abound in Lumbri- 

 cidse to the almost entire exclusion of the truly indigenous 

 forms ; to find these the cities must be left behind. The 

 coincidence is too great to be passed over. This leads to 

 the inference that in the case of these particular genera 

 the forms met with outside the Palaearctic region — perhaps 

 even including North America — are due to carriage on 

 the part of man. Every case of a supposed wide distribu- 

 tion of a species should in the same way be submitted to 

 careful criticism before acceptation as a fact of distribution. 

 Mr Macpherson's record 1 of an African lizard in Cumber- 

 land and Dr Gray's statement of a young crocodile 

 hidden beneath a haystack need no special examination 

 to deny their claims to indigeneity ; but there are plenty 

 of cases like that of the earthworms just referred to. 



On a former page we have dealt with discontinuous 

 distribution as a phenomena explicable in various ways. 



An excellent instance of the discontinuous distribution 

 of a species due to the influence of man is afforded by the 

 common bear (Ursus arctos) of Europe. And here we 

 can, which we could not in the last case, fill up the gaps 

 for ourselves with certainty and not merely with reason- 

 able probability. In a carefully coloured map illustrating 

 the distribution of the bear-like Camivora Dr Greve 2 



1 The Natural History of "Lakeland. 



2 Zool. Jahrbiicher, Vol. vi. Abt. f. Syst. 



