196 Structure of Plants. 



than that of those from South Sweden. One-year-old plants from 

 northern seed were also weaker and smaller than those grown from 

 southern seed. This is what one would expect, for in the north 

 the trees have probably less sunshine, and therefore cannot store 

 up so much food-reserve in the seed. 



I think, then, that there is a large body of evidence from 

 Canada, Sweden, United States, Germany, and Jamaica in favour 

 of the principle that the largest, fattest, or heaviest seeds should 

 always be selected for seed corn. 



It should not be difficult to do this either by some sort of 

 centrifugal machine, or perhaps simply by riddling. 



But there is one important precaution. The particular 

 variety of oats or turnips which would do best when so selected in 

 the valley of the Nith will not be just the same strain which does 

 best in Ayrshire or in England. I have found marked differences 

 in the natural floras of Nithsdale, Annandale, Eskdale, and the 

 country about Kirkgunzeon and Killywhan. 



To get the best results farmers should experiment each on his 

 own farm. Surely the selection of a few individual grains would 

 not involve a very large amount of labour. 



The Uses of Apparently Useless Details in the Structure 

 OF Plants. By the President. 



It has long been a favourite theory of mine that every detail 

 in the structure of a plant has a distinct and definite meaning. 

 I am afraid that very few other botanists agree with me, but yet if 

 I had sufficient time, I think that I could produce an enormous 

 number of cases which go to uphold this belief. I shall, however, 

 just select a very few instances, of which specimens can be ob- 

 tained at this season of the year, and which have either not been 

 published, at least so far as I am aware, or are not commonly 

 known to most British botanists. If one looks at the sepals of 

 these three primulas, the differences are very marked indeed. 

 The Dusty Miller has short bluntish ovate-triangular sepals with 

 a fine mealy farina and a pretty little fringe round the edge. In 

 the minute unfolded bud, one finds that the tiny sepals overlap so 

 as to look rather like the clenched hand of an infant. Then 

 comparing the mature sepals, one can see how this bud condition 



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