32^ 



other indication of insect agency. It is possible that we have 

 here a result of insect action becoming hereditary. If so, these 

 cones would furnish an additional and excellent proof of the 

 principle which Prof Henslow supports by an abundance of 

 ingenious argument and illustration. 



A specially interesting part of the book is the author's sum- 

 mary of his reasons for rejecting the famous Darwinian theory 

 embodied in the aphorism, ** Nature abhors close fertilization." 

 He concludes that the benefits of cross-fertihzation are compara- 

 tively transient, and that naturally self-fertilized plants are, upon 

 the whole, more successful in the struggle for life than those with 

 ingenious appliances for heterogamy. Not a little force is added to 

 Prof Henslow's controversion of some of Darwin's most import- 

 ant doctrines by his quotations from the great naturalist's later 

 writings, showing that the trend of the latter's views, near the 

 close of his life, was directly towards the conclusions here 



■ reached. 



E. E. S. 



Index to Recent American Botanical Literature. 



Arctic Plants grozving in New 



Distribution. James Fowler. (Trans. Roy. Soc. Canada, 



v., (1887), 189-205.) 



Prof. Fowler demonstrates the remarkable fact, that of 257 

 native arctic plants in New Brunswick, -241 are natives of Arctic 

 Europe, and in particular of Scandinavia and Lapland, while but 

 i^"] are indigenous to Arctic East America. He accounts for 

 this distribution by climatal and regional similarities. The old 

 theory is maintained that a homogeneous arctic flora covered the 

 polar regions before the Glacial Epoch, and on the advent of the 

 cold and ice was driven southward on both continents ; that on 

 the recession of the glaciers this flora, decimated and considerably 

 modified, crept back until it reached its present condition, local 

 differences being due mainly to climatal causes. It is a very 

 pretty theory and one could desire no better explanation of the 

 present state of arctic vegetation, if we only knew that its 

 premises were correct. Unfortunately we do not know this, but 

 instead, the researches of Heer have shown that in late Tertiary 

 time the arctic flora was almost tropical in character, and no in- 



