106 MR. MILLER CHRISTY ON THE 
Prof. Rugero Cobelli *, John French +, Alexander H. Gibson }, G. F. 
Scott-Elliot $, I. H. Burkill |, Dr. Paul Knuth f, Rev. E. Bell **, Prof. F. E. 
Weiss tf, Prof. G. S. Boulger ff, Miss Mary L. Armitt $$, the Rev. E.T. 
Daubeny ||, E. G. Highfield 7], and A. A Dallman ***. One of these 
devoted most of a large part of a fair-sized volume to a discussion of the 
problem, but without, I think, contributing anything material to its solution ; 
nor does the latest contribution to the subject (that of Mr. Dallman), though 
painstaking, carry it much further, so far as I can see. 
That so much observation and discussion should have produced so little 
result is not altogether surprising ; for the problem presents (as will be 
found) certain unusual complications. There are some plants whose flowers 
exhibit a highly complicated floral mechanism (the Orchids, for example) ; 
yet the manner of their pollination is fairly obvious. On the other hand, the 
dimorphic heterostyled flowers of the Primulas exhibit a floral mechanism 
which, though highly ingenious, is comparatively simple ttt; yet (as has been 
stated) the precise manner of their pollination has defied investigation and 
remains to this day unexplained. It may be doubted, indeed, if there is 
any problem of the kind more puzzling than that which has been called 
“the Mystery of the Primrese.” 
Three species of the genus Primula are immensely abundant in Britain, 
though one of them is so in one district only. All three species are also 
very common and very widely distributed on the Continent. They are :— 
* Verhandl. der K.K. zool.-bot. Gesellsch. in Wien, xlii. (1893), pp. 73-78. 
+ Essex Naturalist, v. (1891), pp. 120-124. 
[ Trans. Bot. Soc. of Edinb. xix. (1893), p. 156. 
§ Flora of Dumfriesshire, p. 114 (1896). 
| Journ, of Bot. xxxv. (1897), p. 186. 
€ Handb. der Blütenbiologie, ii. (1899), pp. 808-319 (Leipzig, 3 vols., 1898-1905), and 
Handb. of Flower Pollination, transl. by Prof. J. R. Ainsworth Davis, iii. pp. 64-75 
(Oxford, 3 vols., 1906-09). 
** ‘The Primrose and Darwinism,’ by a Field Naturalist’ (7. e., E. B.], (Lond., 1902). 
tt New Phytologist, ii. (1903), pp. 99-105; iii, (1904), pp. 168-171; and Nature Notes, 
xv. (1904), pp. 103-106. 
jt Nature Notes, xv. (1904), pp. 84-86. 
$8 New Phytologist, iii. (1904), p. 170. 
l| Nature Notes, xvi. (1905), pp. 116 & 136-137. 
«4 Knowledge, xxxix. (1916) pp. 113-117. 
*** Journ. of Botany, lix. (1921), pp. 316-322 & 337-345. 
ttt It was, however, Darwin’s opinion that tri-morphic heterostyled flowers, such as those 
of Lythrum Salicaria, present “a more extraordinary and complicated arrangement of the 
reproductive system than can be found in any other organic beings " (see his Introd. Note 
to Müller's * Fertilization of Flowers, p. ix). 
