Variation in the Weasel and Hedgehog. 245 



accept the situation, pregnant as it is with interest, and to 

 welcome each step in the road to its explanation? 



It is, in fact, only to be expected that a mountainous 

 country like Scandinavia, with one flank fully exposed to the 

 damp blasts of the Atlantic, the other chilled by the near 

 proximity of a vast continent, should present us with at 

 least two or even more phases of each common mammal. 

 This is certainly the case, as Dr. Lonnberg points out, with 

 the polar hare, Lepus canescens, and I have shown that it is so 

 also with the squirrel and also probably with the long-tailed 

 field-mouse, Mus sylvaticus. Why, then, should Dr. Lonn- 

 berg be at such pains to demonstrate the occurrence of the 

 " vulgaris " form together with the " typicus" an incident 

 which was not only probable but necessary for the proper 

 appreciation of their role as subspecies? And why should 

 l)r. Lonnberg regard such intergradation both of colour and 

 size as rendering the distinguishing characteristics derived 

 from them unimportant, when in the very same paragraph 

 he shows his thorough agreement with me that tl the variation 

 of the weasel certainly does not lack significance, because 

 intermediate stages occur which unite the extreme forms " ? 



Of Dr. Lonnberg's second paper — " Note on the Indi- 

 vidual Variation of the Common Hedgehog " — I have less to 

 say. I had found what I thought to be solid points of 

 differentiation between the skulls of hedgehogs from England 

 and Scandinavia, whereby all the examples included in 

 a fair series contained in the British Museum of Natural 

 History were readily distinguishable. Relying on the rule, 

 soon learnt in working at mammals, that such differences, 

 even if slight, are usually not meaningless, I assumed that 

 they would be borne out by a larger series of specimens 

 than I at that time had before me. Dr. Lonnberg finds that 

 this is not so; and I can only say that, while I am sorry that 

 my opinion seems to have been erroneous, I am only too glad 

 to find here in the hedgehog another check to those who, 

 while refusing to recognize colour differences, pin their faith 

 with an inconsistent fidelity on what are frequently the 

 shadowy characters of the cranium. Such characters of the 

 cranium, as every year only seems to teach us, may be full 

 of value or worthless just according to the individual idio- 

 syncrasy of the animal in which they occur. They are in 

 many cases not one bit more reliable than those presented 

 by colour, proportions, or size. In fact, in regard to some of 

 the more important cranial characters, such as those of the 



