E. E. IVeiss on Pollination of the Primrose. 99 - 
OBSERVATIONS ON 
THE POLLINATION OF THE PRIMROSE, 
By F. E. Weiss, D.Sc. 
A considerable amount of uncertainty exists as to the manner in 
which the pollination of the primrose is effected. Darwin 1 
has recorded how rarely insects can be seen during the day visiting 
the flowers of the primrose, and became to the conclusion that they 
were commonly fertilized by nocturnal Lepidoptera. Writing in 
1897 on the fertilization of spring flowers on the Yorkshire coast 
Mr. Burkill 3 says with regard to the primrose: “the fertilization of 
this plant is yet unexplained. None of the insects seen on it 
through many hours of watching are sufficient for its fertilization.” 
He was consequently inclined to accept Darwin’s conclusion as the 
correct one. In a more recent publication entitled “The Primrose 
and Darwinism” the author, “ A Field Naturalist” states it as his 
belief “ that the primrose gives unimpeachable evidence that self 
fertilization of heterostyled plants is the natural and legitimate 
fertilization as being fully productive.” This conclusion so directly 
at variance with Darwin’s explanations of the importance of hetero- 
styly as ensuring cross pollination was largely based on the absence 
of insect visitors to the primrose, of such insects at least as could 
effect the pollination of the flowers. Only four such visitors were 
observed by “Field Naturalist,” “after seeing and examining 
thousand and thousands, we might say millions of the flowers.” 
Other British botanists 3 , it is true, have recorded the visits of 
various insects to the flowers of the primrose, but their observations 
do not seem to have been regarded as conclusive by Darwin, 
Burkill, or “ Field Naturalist.” Knuth 4 has given a complete sum¬ 
mary of the observations made upon this subject up to the year 
1899 both by himself and others, yet one cannot help feeling that 
there is a considerable amount of conflicting evidence, for while 
Knuth and Scott Elliot look upon Bombus hortonim as one of the 
most important agents of pollination, Darwin states definitely 5 that 
1 Darwin, C. Forms of Flowers, p. 36. 
2 Burkill, I. H. Journal of Botany, 1897. 
3 {[.) Briggs. T. R. Archer. Journal of the Plymouth Insti- 
tion, 1871-72. 
tii.) Miller-Christy. Trans. Essex F'ield Club, 1884. 
(iii). Scott-Klliot. F'lora of Dumfriesshire, 1896. 
4 Knuth, P. Blutlienbiologie, 1899, vol. II., p. 313. 
‘ Darwin, l.c. page 56. 
