Sunshine, Rain, and Wind 



the character of flowering plants, and even to give some 

 species a distinct advantage over others. 



Along railway lines in Southern Sweden the flowers 

 on the north side of the line (with a southern exposure) 

 will be chiefly Barbarea vulgaris, Convolvulus arvensis, 

 Anthemis tinctoria, and Alyssum calycinum, and there 

 is no close carpet of mosses but only small tufts 

 of Ceratodon, Tortula ruralis, and Funaria. But on 

 the south side (with a northern exposure) there is 

 a close moss carpet (Hylocomium), and the common 

 plants are buttercups (R. acris), grasses such as Aira 

 caespitosa and Cerefolium silvestre.^^ 



There is a peculiar reddish colour which the reader 

 must have noticed on plants growing in very exposed 

 places, and which is due to a special substance called 

 anthocyan. This colour seems to be directly produced 

 by the effect of certain kinds of sunlight (the violet and 

 ultra violet rays). But when once formed it protects 

 certain valuable ferments or enzymes, such as diastase 

 (w^hich changes starch into sugar), from being destroyed 

 by those same violet rays. So that in anthocyan the 

 evil itself seems to have produced exactly what is 

 required in the way of a remedy.^^ 



Sunshine also helps to produce such substances as 

 carotin, which are found in flowers,^^ and as we have 

 seen intensifies not only flower colours but also perfumes. 

 Nor is it only colour that is affected but also the number 

 of stamens. In warm places it has been found that the 

 chickweed has more stamens than elsewhere. On such 

 a plant as the common Bocconia the number both of 

 stamens and carpels is always greater in those flowers 

 that are well placed as regards light and which are well 

 supplied with nourishment.^-^ This effect of nourishment 

 and more genial conditions generally is also very well 

 seen in poppies (P. Rhceas) and marsh marigolds. As 



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