402 LABRADOR 



piration, but directly increases the tendency to low, shrubby 

 growth, and favours anemophilous adaptations (i.e. those 

 using the agency of the wind) for pollination and for dis- 

 semination of fruits. Differences in the nature of the soil in 

 Labrador would seem to be not great, and to derive their 

 importance mainly from their ability to conserve moisture, 

 free from admixture with growth-hindering acids and salts. 



There are, however, some further direct and important 

 influences. One of them, not often mentioned but very 

 evident, is the scarcity of insects that aid in pollination. 

 The proportion of flowers that are anemophilous, or wind 

 fertilized, as compared with those that solicit insect aid, 

 is considerable, as might be anticipated from the fact that 

 flower-haunting insects are rare. Yet there are many 

 flowers of the latter type, though mainly of species that do 

 not absolutely depend upon insects for the fertility of their 

 seeds. 



Another positive influence is the relatively protracted 

 illumination during the period of growth. This, like many 

 other influences operative here, has been shown to have a 

 tendency to diminish herbaceous growth, affecting the size 

 both of the plant and of its leaves; and to favour repro- 

 duction. The devices that protect against too great trans- 

 piration often serve at the same time to secure protection 

 against excessive and prolonged illumination. 



Finally, the shortness of the season of growth is of large 

 importance. It is this which forces a large proportion of 

 the plants that are to survive under the conditions which 

 Labrador supplies, to develop in a previous season the em- 

 bryonic preparations for the leaves and flowers that are 

 to appear the following summer. Hence is derived the 



