BY THE TEESIDENT. 189 



books, would afford me foundation for an address ; but I tliought 

 that, after all, it was iDreferable for those who take an interest 

 in Science to read the works themselves, to hearing a garbled 

 report of them second-hand. I therefore felt that I must take up 

 some other subject ; but before I proceed, I may just mention one 

 point to which I alluded in my last address, that was curiously 

 illustrated in our Church decorations of last Christmas. 



Every one must have noticed the remarkable absence of holly 

 berries in this district, and the same scarcity was felt over a con- 

 siderable portion of England. The question arose, " How is it that 

 holly berries are so scarce?" It was attributed by some persons 

 to the early frosts ; but I for one expressed an opinion that it was 

 due to a want of certain insects in the spring ; and I am glad to 

 perceive that in a letter addressed by Mr. Darwin to the 'Gardener's 

 Chronicle,' he bears out entirely that view. He points out that the 

 holly is what is known as a dioecious tree — that is, there are 

 separate male and female plants, — and it is requisite that the pollen 

 from the one shall be brought to the other before the flowers are 

 fertilised to produce seed. This is done generally by means of 

 bees, as he has ascertained by actual experiment some years ago. 

 It appears, therefore, that the absence of holly berries arose from 

 the deficiency of bees. Mr. Darwin also observed, in looking over the 

 clover fields which were in flower in his neighbourhood, that there 

 was there also comparatively a small number of humble-bees ; and it 

 crossed his mind whether — in consequence of this — there might not 

 prove to be some failure in clover seed, as clover is mainly fertilised 

 by means of humble-bees. Curiously enough, he subsequently re- 

 ceived a letter telling him that there was a deficiency in clover 

 seed, and farmers could not understand why the seed had not set. 

 I do not know whether the clover seed was affected to any great 

 extent in this neighbourhood ; but there is no doubt this is one of 

 those cases in which " great effects from little causes spring," and 

 that the presence or absence of a few insects affects the prosperity 

 of farmers and others engaged in agricultural pursuits. As Fuller 

 observes of our Hertfordshire Pope, Adrian the Fourth, who was 

 choked by a fly — " Anything next nothing, be it but advantageously 

 planted, is big enough to batter a man's life down to the ground." 

 No doubt the absence of his seed-crop is not equal to the batter- 

 ing down of a farmer's life, but still it may materially affect him. 



But to return from this digression. I was saying that I found 

 a difiiculty in deciding what would be best adapted to speak upon 

 this evening. I thought probably that you would have had during 

 this year almost enough of purely geological subjects. It then 



