THE VEGETATION OF TEMPERATE AND ALPINE SIKHIII. 109 



regions; nine are confined to the North Temperate zone, one — Sela- 

 gincoe — is South African, with the exception of the Glohularia of Europe 

 and Lagotis, a Himalayan, Arctic, and Alpine genus. 



A further examination brings to light the fact that every order 

 in this region (likewise in all others where they prevail) abounds in 

 plants having brightly-coloured flowers, excepting the Apetakc, and, 

 even in those, the high level Euphorbias are differentiated sufficiently 

 by their showy involucral leaves ; therefore, to apply the case shortly 

 without putting forward an absolute assertion, of the 50 orders named 

 above, only seven can be characterized by having inconspcuous 

 flowers. 



There are a few details in the phenomena of vegetation in the 

 Alpine region of Sikhim which are deserving of a brief notice. 



The first is the preponderance of shrubby and herbaceous plants 

 with bright-coloured flowers. For these the only fertilizing agents 

 are apparently bees, of which there are a great variety of species, 

 belonging to the kind known as bumble bees in England. Other 

 orders of insects are rare ; and butterflies, flying as they do in count- 

 less multitudes at lower levels, are here too uncommon for their 

 agency to be taken into serious consideration. 



As the higher orders of plants require the aid of insects for their 

 propagation, it naturally follows that, as bees are here the commonest 

 gToup of insects, the flowers from which they extract nectar and 

 pollen for honey, will enjoy most opportunities for the due 

 perpetuation of their race, those which require specialized forms of 

 insects, such as flowers with elongated and narrow corollas, will be 

 entirely absent, dioecious forms with inconspicuous flowers will 

 share the same fate ; and the only species adapted to survive this 

 restricted method of existence will be plants with bright shallow 

 flowers, with coloured bracts surrounding a less apparent inflorescence, 

 or with broad corolla tubes into which bees can enter with ease. 



The structure of the prevalent orders shows that the plants most 

 fitted by nature for the visitation of bees and similar insects are the 

 commonest at high elevations. As plants with brightly-coloured 

 flowers will naturally first attract the attention of insects, it would 

 appear that they have become so for no other definite reason, although 

 the greater intensity of light consequent on a more attenuated and 

 clearer atmosphere has also been advanced as an exjilauation of the 

 fact. 



With the exception of the musk Delphiniums, many labiates, 

 composites, and some primroses, all the plants are remarkably devoid 

 of odour. No rhododendron has scented flowers, and the species of 

 that genus abounding in aromatic glands over their whole surface are 

 low-growing bushes, extensively gregarious, which may have acquired 



