I30 



HARDWICKE'S SCIENCE-GOSSIP. 



colour, contained such only in some portions, others 

 being quite devoid of them (Fig. 93 a). Numerous 

 round bodies were lying between the separate light 

 and dark hyphre, some with highly-refractive portions 

 inside ; occasionally four, or more or less, were 

 attached to each other (Fig. 93 c, spores?). 



To see whether the organisms were actually 

 growing in their different solutions, and had not come 

 in accidentally, small portions of each were put into 

 well-stoppered bottles, and after six to eight weeks 

 they had grown quite considerably. 



These organisms all seem to belong to the class of 

 the bacteria, but I have not been able to ascertain 

 either their names or anything about their life-history. 

 I would be very thankful for any suggestions on the 

 subject. 



I have got any amount of material, and I will be 

 very glad to exchange some of the same with ;any of 

 the readers of Science-Gossip. 



Otto V. Darbishire. 



BaUiol College, Oxford. 



THE BEE AND THE WILLOW. 

 By G. W. BuLMAN, M.A. 



THE willow-haunting propensities of bees are 

 conspicuously displayed in the spring ; they 

 are probably familiar to many. It is Grant Allen 

 who observes that "you hardly ever see a willow 

 catkin in full bloom without a bevy of its attendant 

 fertilising insects." 



It is to the theory implied in this word "fertil- 

 ising " that I wish to call attention ; I cannot think 

 that the willow depends chiefly on bees, or even that 

 it is at all frequently fertilised by the same. It is 

 rather to be believed that it is wind-fertilised, like the 

 majority of dioecious plants. 



I cannot bring forward conclusive evidence ; but 

 what I have, points emphatically in the above direc- 

 tioH. While I set forth my small quantum of evidence 

 — the fruits of a few moments' observation on a 

 spring afternoon — let me call the attention of others 

 to the matter as a question requiring solution. 



In the first place, given a species bearing its 

 stamens and pistils on separate plants, how is insect 

 fertilisation to be accomplished? Obviously by the 

 insects passing frequently from a plant with the one 

 sort of flowers to a plant with the other. If we 

 imagine them making alternate visits first to a male 

 and then to a female flower in regular order, then 

 each of the latter has a fair chance of fertilisation. 



But if a bee visits say fifty male flowers, and then 

 goes and pays the same number of visits to female 

 flowers, only a few of the first visited of the latter 

 will probably be fertilised. If a bee gets its fill on 

 one sort of flower, it will accomplish no fertilisation 

 at all. 



We should be inclined to infer, h priori, from our 



general knowledge of the habits of bees, that one of 

 these latter would happen. 



Let us, however, see what the bees are really 

 doing. Here by the river-side are the willows in full 

 flower. Very large numbers of bees are buzzing 

 about the male catkins of those large bushes ; on the 

 neighbouring ones with female catkins are consider- 

 able numbers, but not nearly so many as on the 

 former. 



In the first case they are gathering pollen ; their 

 thighs are laden with the golden grains : in the latter 

 honey alone is presumably their object. 



I do not know whether bees usually carry on these 

 two operations at the same time or not ; but in tliis 

 particular case, since the bees on the female blossoms 

 have no load of pollen, it may be presumed that they 

 have not recently been on the male catkins, and are 

 not therefore fertilising the former. I do not wish it 

 to be inferred from this single observation of the 

 bees' habits that bees with loads of pollen do not 

 often fly to female catkins ; it is rather brought 

 forward as a point for further investigation. 



Now both of the above facts — the difference in the 

 number of bees on stameniferous and pistiliferous 

 plants, and the absence of pollen loads on these 

 visiting the latter — point to the conclusion that the 

 willow is not as a rule fertilised by bees. And when 

 we reflect that every passing breeze may carry cloud& 

 of the fertilising dust to the stigmas, the inference 

 seems obvious that the willow is frequently wind- 

 fertilised, and that it could get along very well 

 without the bee. Yet we find Mr. Grant Allen 

 asserting that "the willows depend entirely for the 

 due setting of their seeds upon winged allies." * 

 And if the willow is really wind-fertilised, the 

 existence in its flowers of honey is — on the bee- 

 selection theory — anomalous. Also, according io- 

 certain upholders of the same theory, insect visits- 

 are a disadvantage : 



" The very same insect interference which proves 

 so beneficial to insect-fertilised plants is the deadliest 

 danger of their wind-fertilised allies, and is guarded 

 against by a profusion of minute devices." f 



As is well known by students of Virgil, the bees'' 

 frequent visits to the willow were noted some 1900' 

 years ago ; to-day, in spite of the insect's selection, 

 its flowers are neither blue nor complex. What caa 

 we think of selective action applied perseveringly for 

 some 2000 years without producing any effect?' 

 Upholders of natural selection consider — somewhat 

 unreasonably, surely — such questions unfair ; they are 

 wont to answer that there has not been time ; that 

 your two thousand years is but a drop in the bucket 

 required. 



Such answers are most unsatisfactory. The geo- 

 logist who tells us that rock-masses many miles \w 



* "Knowledge," Feb. 23, 1883. 



t Grant Allen. " Knowledge, ' June 8, 1883. 



