134 MR. MILLER CHRISTY ON THE 
concluded * that “None of the insects seen on it... [was] sufficient for 
its fertilization.’ Mr. John French, a good field observer, has remarked on 
the apparent “absence of fertilizing agents.” The somewhat-imperfect 
observations of the Rev. E. Bell and the more complete ones of Prof. Weiss, 
point strongly in the same direction. Still more to the point are the remarks 
of the Rev. E. T. Daubeny, who says f, after carefully watching Primroses 
during two springs :—“I am... impressed with the way ordinary insect 
visitors of our spring flowers neglect the Primrose.... If its fertilization 
depended upon them, the primrose would soon cease to exist." 
The position now reached seems to be this :—On the one hand, the long- 
tongued insects which are obviously capable of pollinating effectively the 
flowers of our Primulas, and seem clearly intended to do so, visit the flowers, 
to all appearances, too seldom to effect their pollination adequately. On 
the other hand, the flowers are frequented abundantly (and, to all appear- 
ances, pollinated largely) by certain minute insects which are of a kind no 
one can regard as intended by nature to pollinate them §. 
How is this paradoxical result to be explained ? 
VII.— Conelusion. 
From the foregoing, it becomes clear that, thus far, a satisfactory solution 
of the problem has not been reached. It is, therefore, necessary to search 
further for one. In so doing, one may well wonder whether the flowers of 
our Primulas may not be pollinated normally by some long-tongued insects 
which have not yet been detected in the act of visiting them. 
This appears, indeed, to be the correct solution. There seems, in short, no 
alternative but to fall back on Darwin's hypothesis that pollination is 
* Journ. of Botany, xxxv. (1897), p. 186. 
f Essex Naturalist, v. (1891), p. 120. 
[ Nature Notes, xvi. (1905), p. 136. 
$ That, in the Primrose, comparatively few of the flowers which bloom ever set seed is 
proved by even superficial observation. Mr. French doubts (Essex Nat. v. p. 120) whether 
as many as one per cent. do so. Mr. Highfield has observed (see Knowledgs, xxxix. p. 115) 
that “ only a small proportion of flowers on a plant, rarely exceeding half, sets its flowers.” 
Yet that all the three species contrive somehow to secure pollination to some extent is 
certain; for all produce regularly an abundance of seed. This is more especially the case 
with the short-styled plants. Darwin showed long since (‘Forms of Flowers,’ pp. 17-26) 
that these are more prolific than the long-styled plants, and I have since demonstrated 
the fact on far fuller and more conclusive evidence (Trans. Essex Field Club, iii. 1884, 
pp. 163-169 and Tables V.-XV.). Yet, as I have also shown elsewhere (op. cit. pp. 157-163 
and Tables I.-VI.), long-styled plants are in nature slightly more numerous than short-styled- 
Both facts may, perhaps, be connected in some way with the fact that, as shown herein, large 
quantities of polien are regularly stolen from short-styled plants by predatory insects. 
