INTRODUCTORY ESSAY. 107 



Mora predominates throughout the drier regions of the Hima- 

 laya*. Siberian forms are^ however, by no means confined 

 to the drier parts of the chain, but may be observed even in 

 the most humid regions of the Himalaya, and occasionally 

 even on the mountains of tropical India. Thus Artemisia and 

 Astragalus, which are perhaps the most characteristic genera 

 of the Siberian type of vegetation, are not only abundant 

 throughout Tibet and the interior Himalaya, but are repre- 

 sented by a few species in the plains of the Panjab, on the 

 outer slopes of the western Himalaya, and even on the Khasia 

 mountains. Spircea Kamtchatica, chamcedrifolia, and sorbi- 

 folia, and Paris polyphylla, are also Siberian forms which 

 extend into the rainy Himalaya ; and Corydalis Sibirica and 

 Nymphcea pumila are remarkable instances of specific identity 

 between Khasia and Siberian plants t- 



5. The European type. — The extent to which European 

 plants abound in India has never hitherto been even approxi- 

 mately appreciated. Dr. Royle was the first to indicate this 

 affinity between the vegetation of the eastern and western 

 continents of the old world ; and throughout his writings we 

 find constant evidence of his never having lost sight of this 

 being a marked feature. Had the collections, upon which he 

 founded his conclusions, been critically compared and worked 

 out, the keystone to the whole system of distribution in 

 Western Asia could not have escaped him, which does not 

 rest so much upon a number of representative species, as 



* As a few instances, besides the many Rcmunculacece and Fumanacece enu- 

 merated in the pages of the present volume, we may mention Tauscheria de- 

 sertorwm, Biehersteinia odora, Potentilla Salessomi, muUifida, and Ufwrea. 

 Chammrhodos sabulosa, Pyrus baccata, Astragalus contortwplicatus, densi- 

 flonis, and subulatus, Fhaca frigida, Oxytropis diffusa, Cicer Soongancwm, 

 Sedum quadrifldum, Artemma Dracunmlus, scoparia, Tomrnefortiana, fasci- 

 culata, and salsoloides, Sausswrea latifoUa and pygmaa, Mulgedium Tatan- 

 cum, OsmotTiamnns fragrans {Rhododendron anthopogon, Don), Salix amgus- 

 tifolia, Populus haUamifera, Carex microglochin, stenophylla, physodes, mpma. 

 and tristis. 



t It is curious to remark that there are in Siberia a certain number of forms 

 indicative of tropical Indian types, as, for instance, Menispermum and Anandria. 



