Mr Harvie-Brown on the Squirrel in G^reat Britain. 63 



probability is that this safety-valve was re-opened by the 

 planting there, just in time to save the remnant. No more 

 forcible illustration, perhaps, of the natural law that a given 

 area will only support a limited number of individuals can 

 be found, than in the abnormal increase of the Pallas sand- 

 grouse, and consequent " irruption " of the species into Europe 

 in 1863 {vide Ihis, 1864). 



In this connection Sir Dudley Marjoribanks, Bart, of 

 Guisachan, Inverness-shire, writes (in lit) as follows : " In 

 1862, I saw a dead squirrel on the bridle path at Ardnamul- 

 loch, fourteen miles west of Guisachan, and at the end of the 

 district of natural pine and birch. It was at the end of the 

 stalking season, and the squirrel appeared to me to have died 

 from stress of weather and not from violence. I heard of 

 another the same year being found dead at Ault-beith, ten 

 miles further west, and where there is not a tree within 

 miles." Thus it will be seen that they had distributed them- 

 selves almost to the very far upper end of Glen Grivie, 

 almost to the base of the backbone of mountains which 

 form the natural boundary between the faunal districts of 

 Moray and West Eoss (vide Map). Significant is the 

 further statement by Sir Dudley Marjoribanks, that " The 

 squirrel here is a shabby little animal in comparison with his 

 southern brother. I doubt whether he would weigh half as 

 much in the scales — and he is not nearly so rich in colour." 

 Therefore, feeding principally upon natural growth, being of 

 an inferior and smaller type, wandering far in search of better 

 food, they would in all probability succumb all the more 

 easily to severe weather such as was experienced in the 

 winter of 1860-61 and 1861-62.* 



* I have elsewhere in this essay more fully pointed out also that the 

 severity of the winter of 1878-79 banished the species from many localities, 

 whilst the sudden increase again of the species, later in the year 1879, 

 pointed to an emigration caused, in the first instance, by the intense cold. 

 At the time when they became extinct, or nearly so in Scotland, the forest 

 ground was much curtailed, and the loopholes of escape were not so numerous. 

 Failing a natural migration, as already explained, they would die {vide 

 Proc. Glascj. N. 11. Sac, 1879). 



