FERTILIZATION OF SPRING FLOWERS ON THE YORKSHIRE COAST. 189 



possible that this is a reason for the early flowering of many plants ; 

 in the case of Tioisilario and some others it is probably otherwise, 

 and competition with other similar blossoms is avoided by their 

 early flowering. 



The micertainty of spring weather must affect the plants through 

 the insects visiting them. The severe winter of 1894-95, by killing 

 great numbers of small mammals — field-mice, &c. — probably had 

 somethiug to do with the abundance of the Muscidte in the end of 

 tbe following March, and perhaps the ScatophagidiB may have been 

 more abundant in 1896 because the mild winter permitted their 

 dung-feeding ]av\iG to continue growth through the greater part of 

 it. Headers will remember Darwin's'-' classical instance of the effect 

 of cats on the abundance of clover; just such a case of the compli- 

 cated inworkiug of things is the apparent effect of a severe winter 

 on the fertilization and consequent fruit-setting of plants flowering 

 later. Writing of the island of St. Kilda, in the Outer Hebrides, 

 Gibsonf says, "some species, at least in certain years, are not 

 fertilized at all, e. g. Vicia seinum, Trifolium pratensc, and Lunicera." 

 How seasons affect the seed-setting of different species is a question 

 for the future. Dureau de la Mallef says that in thirty years, on 

 one undisturbed moor, he observed five or six successive changes 

 by which Lcriuminosm dominated over the grasses, and in turn 

 grasses over the LcguminoscB. Were such changes in any degree 

 the effect of want of fertilization ? 



Hermann Miiller has written, "the uniform perfection which 

 Axell supposes to exist in Nature h.is no real existence. "§ Some 

 observers among us have dazzled their eyes by the mechanisms of 

 the most nearly perfect of flowers — e.fj. orchids — and have failed to 

 see the imperfect around them ; others have blindfolded themselves 

 to tbe advantages of cross-fertilization. To neither should we trust 

 too much. I am convinced that the truth lies in the mean, and if 

 this paper has suggested much that is imperfect, it has fulfilled its 

 purpose. 



Lastly, I must express my thanks to those who have helped me 

 in the field — my father, my brother, and Mr, J. C. Willis ; and, for 

 whatever is of entomological worth, to my kind entomological 

 friends Dr. D. Sharp, Messrs. G. H. Verrall, E. Saunders, and 

 C. Warburton. 



* Origin of Species, chap. iii. Cth ed. i. p. 90; London, 1872. 

 t Loc. cit. p. 155. 



J " M6moire sur rAltcrnancc," Annales des Sciences Nat. Ser. i. vol', v. 

 p. .^53 (1825). 



§ Fertilization of Flowers, p. 589. 



