HANDBOOK OF FLOWER POLLINATION 861 
But the great development in branch of botany, and the abun- 
dance of new material, rendered necessary an entirely new work, 
f Mii 
connection with e oxteeminte in hybridisation, made numerous 
observations on the pollination of flowers in the second half of the 
eighteenth century; a oie of irre bed forms a frontispiece to 
the volume. An account of Sprengel’s work is accompanied by a 
reduced parton of the title-page of the Entdeckte Geheimniss ; 
and oe his a of the subject is followed in the work of Darwin 
nasa subsequent ai ee who were stimulated 
oti of F élix Piateay on re attraction of insects by flowers are 
discussed in a Supplement later in the book. Plateau ssibenaed 
that insects are guided to flowers, not by their bright colours, but 
by their sense of smell ; but Knuth, like other critics of Plateau’s 
work, is unable to follow him. “His ex periments,’’ Knuth says, 
‘‘only show that the sense of smell perhaps guides insects to a 
greater extent than has hitherto been supposed.” 
The Second Section forms an exhaustive review of the present 
standpoint of flower-pollination, and occupies nearly two hundred 
pages. It includes a summary of the various arrangements deter- 
mined by distribution of sexes in time — tie by different forms 
of flower and other factors, and some unt of the insects which 
visit flowers. The most important part ig & grouping of flowers sug- 
gested by the author, after consideration of the groupings advanced 
by Delpino and Miiller, according to the mechanism of pollination. 
The remainder of the volume, comprising nearly one-half, is 
occupied with a bibliography, which includes the citations in the 
original and additions which bring the eonend down to Jan. 1st, 1904. 
“Professor Prefatory Note supplies the history ‘of the 
preparation of ma rag edition, which was begun by Dr. Gregg 
Wilson and completed by Professor Ainsworth Davis, with the 
assistance in the ee 3 portion of Mr. J. M. F. Drummond, 
Mr. 8. and Dr. F. E. esis ritsch. The second volume of the 
Handbuch is a fos ecial account of all known observations “gee the 
anner ion m 
ont Baroy ; the Enelish edition will if eceeunes follow in due 
A. B. R. 
JournaL or Botany.—Vou. 44. [OcropEr, 1906. ] 2D 
