158 PROCEEDINGS OF THE 



IV. — Remarks on the occurrence of Alpine and Suh-alpine Forms near 

 the Sea Level in Insular Situations. By Mr John Shaw. 



The author of this paper first referred to the various facts 

 which he had observed in such places as Lochgoilhead and the 

 outer Hebrides. Some Alpine species there flourished at fifty or 

 a hundred feet above the sea level. Negative evidence is, how- 

 ever, afforded by the entire absence, in such localities, of the 

 delicate ephemerals of the plain. Only the more hardy species 

 prevail. He then showed that the mean summer heat of such 

 places was lower than that of inland regions, and that, from the 

 nature of exposure to the sea, the climate Avas subject to greater 

 vicissitudes, and was more severe — causes which undoubtedly 

 brought about such apparent anomalies in distribution. After 

 stating that island floras in any one region were less varied than 

 inland floras in the same region, and speaking of the great paucity 

 of forms in all insular places, Mr Shaw pointed out the application 

 of the whole theory to some anomalous facts in the mountain 

 distribution of plants. He thought it was possible to explain the 

 occurrence of such plants as the sea pink (Aremeria maritima), the 

 scurvy grass (CocJilearia officinalis), on mountain summits in tliis 

 way, by reference to the period when the area of Great Britain 

 was considerably less. The theory also gave the best explanation 

 of facts known to all practical botanists familiar Avith mountain 

 floras, such as the occurrence of species belonging proj)erly to the 

 plain being found in the neighbourhood of springs far up the 

 mountain side, in the tracts occupied by Alpine forms, and the 

 correlative fact of the descent of Alpine species to the plain in the 

 immediate vicinity of, or in contact with, water. 



December 18th, 18G6. 

 Mr John Shaw in the chair. 



SPECIMENS EXHIBITED. 



Mr James Coutts exhibited a series of eggs of the common lap- 

 wing {Vanellus cristatus), showing many curious deviations from] 

 the ordinary shape and colouring, with a selection of other species! 

 from his OAvn cabinet, on which he made a few remarks, pointing] 

 out the necessity of having oological collections properly authenti- 



