THE COMMON SHREW 93 



than females, but this is not supported by the figures given above for 

 British shrews, amongst which no recognisable difference in size between 

 the sexes has been shown to exist. 



Proportionate lengths: — Tail (without end hairs) about -5; hind 

 foot about -17 to -18; ear about -i of head and body. 



The weight (in grammes) shows a seasonal variation corresponding 

 to the dimensions. Adams's twenty-four males noticed above averaged 

 12, with a minimum of 10 (once) and a maximum, reached three times, 

 of 14. The discrepancies were generally due to the amount of food 

 contained in the stomach. Adams's eighteen females varied between 9 

 (once) and 16 (twice), and averaged 13-1, their superiority over the males 

 being due to the fact that many of them contained embryos. An 

 increase of weight after March is independently corroborated by 

 Kinnear (MS.). The facts have an important bearing on the much- 

 discussed autumnal mortality discussed below on pp. 104-108. 



Skull: — Greatest length, 19 ; basal length in middle line, 16 ; palatal 

 length in middle line, 8 ; length of upper tooth-series, 8 to 8-5 ; ditto 

 of lower, 7' 5 to 8 ; greatest breadth, 9; breadth at constriction, 4. 



Status, etc. : — The distribution, both modern and geological, of 

 Sorex araneus points to its having first appeared in Britain at a 

 comparatively recent date. As compared with 5. minutus, its greater 

 plasticity and more marked tendency to individual variation indicate 

 a more recent species. In its more complicated changes of pelage it 

 is more specialised, but its greater size and less elongated body denote 

 a more generalised form. 



Distinguishing characters : — The larger size, shorter and less hairy 

 tail, shorter and more slender nose, and generally more striking, usually 

 tricoloured, coloration, with the distinct pattern of the teeth, make the 

 identification of the Common Shrew an easy matter. The character- 

 istics of the Pygmy Shrew will be given under heading of that species. 



The small size, quite as much as the retiring habits of the 

 Common Shrew, makes observation of its movements difficult.^ 

 Its long and pointed snout, flexible form, and compact velvety 

 coat, enable it to pass through the closest herbage, or beneath 

 the carpet of dry leaves in the coppices and woodlands, in which 

 situations, as well as in the open fields, whether of grass or 

 tillage, it seeks its food. Its habit is to pass into or through any 

 crevices or passages which may come in its way, and thus it 

 probably avoids the construction of burrows on its own account. 



' See, however, Douglas English's Some Smaller British Mammals, Bousfield and 

 Co., Ltd., London, undated. This little book contains a number of interesting 

 photographs. 



VOL. IL G 2 



