94 THE BIOLOGY OF THE SEASONS 



possibility of having ready-made buds in position foi 

 unfolding. In some cases, such as the alder, even the 

 flower-buds are made the previous Summer. It is inter- 

 esting also to notice, what Grant Allen points out, that 

 many of our early flowering trees, like lilac, hawthorn, 

 and laburnum, are plants which have a long life before 

 they flower. They have a prolonged nutritive or vegetative 

 period before reproduction begins, and this is doubtless 

 one of the conditions of their hardiness. Another, even 

 more frequent, adaptation to early flowering is the posses- 

 sion of an underground store in the form of rhizome, corm, 

 or bulb, as may be illustrated by dog's mercury, primrose, 

 coltsfoot, celandine, hyacinth, and snowdrop. 



While those Spring flowers that have only stamens 

 and pistil may be regarded as persisting on primitive lines, 

 there are others which may be regarded as persisting on 

 juvenile lines. We mean that they tend to be bud-like 

 as if some slight arrestment occurred in the opening of 

 the blossom. This may be illustrated by crocus and globe- 

 flower. 



Another general impression that we get when we take 

 a wide survey is that the colours of the early flowers are 

 lighter than those of summer, and that colours deepen 

 as the sunshine increases. Of course, there are many 

 exceptions ; but many of these, such as tulips, hyacinths, 

 daffodils, crocuses, irises, are bulbous plants, which places 

 them in a very different position from ordinary annuals 

 and biennials. The whole subject of pigments, alike in 

 plants and animals, is exceedingly difficult, and one must 

 beware of hasty generalisation. The same colours may 

 depend upon different pigments ; the same pigment may 

 have different colours ; a very slight change in the alka- 

 linity or the acidity of the cell sap may produce a great 

 difference in the colour of a pigment. And while progress 



