OBSERVATIONS ON INDIAN PRIMULAS. 



197 



Garhwal, Chamba, and Kashmir, are forms that reappear in 

 Afghanistan, Persia, Central Asia, Turkestan, and Europe. 



It may be here remarked that the Himalayas trend northward 

 as they pass from east to west. Hence 



1. Kashmir lies between 33 0 and 36 0 north latitude. 



2. Kumaon and Bashahr lie between 29 0 and 31 0 north latitude. 



3. Nepal between 28 0 and 30 0 north latitude. 



4. Sikkim and Bhutan between 27 0 and 28 0 north latitude. 

 What influence this may have has not as yet been ascertained, 



but it is curious that the number of the species greatly multiplies 

 as we pass E.S.E. And what is more curious still, this property, 

 whatever it be, seems to continue to increase in value until Yunnan, 

 a province of S.W. China, becomes a new centre of Primula life and 

 one even greater than that of Sikkim. 



5. Yunnan may be said to lie between 23 0 and 27 0 north latitude, 

 thus entirely to the south of Sikkim, the link of connexion being 



6. Manipur and the Shan States, between 24 0 and 26 0 north 

 latitude. 



We have this remarkable genus, which is dispersed along the 

 great mountainous backbone of the world, evolving into at least 

 two great types, as it is diffused from the Eastern Himalaya. Some 

 years ago a paper of mine on Primula was published in the Linnean 

 Society's " Journal." Since then I have seen cause to modify my 

 views very greatly, and the progress made, both in India and China, 

 has practically antiquated anything written so long ago as 1881. 

 In my paper, however, I hinted at a classification, based on the 

 vernation, or method of folding and packing of the leaves within 

 the bud. This, I admit, is a distinction that botanists are not likely 

 to appreciate very much, since it can with difficulty be detected in 

 dried specimens. But I am addressing gentlemen who are familiar 

 with the cultivated Primulas, and I make bold to think they may 

 not object to a character that can be seen readily enough in the live 

 plant. Everyone is familiar with the fact that in the common 

 English Primrose and Cowslip the two margins of the young leaves are 

 rolled up inwards towards the midrib on the under surface of the 

 leaf. Equally- familiar is the fact that in the Auricula or ' Dusty 

 Miller ' the one margin of the leaf is rolled on the upper surface and 

 within the opposite margin. The former condition is denominated 

 " re volute " and the latter " convolute." They are conditions very 

 largely characteristic of two of the most important assemblages 

 of Primroses in the world, namely the Indian and the European. 

 But while Europe possesses both types, no example of a convolute 

 Primrose has hitherto been met with in India, or, I believe, in China. 

 There is, however, a third condition of vernation seen in Primula, 

 namely " conduplicate." The leaves in this condition are simply 

 closed together, the upper surface of the right-hand side of the blade 

 being brought into contact with the left, like the closing of the pages 

 of a book. Now this condition prevails in Africa (Abyssinia more 



