50 PLANT-LIFE ON LAND [CH. 



are formed at the expense of the materials which the 

 co-operation of the foliage-shoot with the root-system 

 has been able to produce under the influence of 

 sunlight. But in the case of many of the plants that 

 expand their flowers in the winter or early spring the 

 matter is not so simple. We see the Snowdrop or 

 Crocus emerge from the soil, and we are apt to forget 

 the swollen underground parts from which they 

 sprang, and from whose stores they drew their 

 sustenance. Still more are we unmindful of the 

 coarse leafage which, following on the flowers of 

 the preceding year, produced by its activity the 

 very materials which we see in the spring worked 

 up into the flowers that we prize. The fact that 

 those materials are stored up out of sight so long 

 before in the buried bulb or corm breaks the con- 

 tinuity of observation, and provides the excuse for 

 forgetting their existence. It is needless to elaborate 

 illustrations of the simple fact that nutrition must 

 precede propagation. However indirect the sequence 

 of events may seem, some form of vegetative shoot 

 precedes the flower with invariable constancy in the 

 individual life of the higher plants. 



As in the preceding paragraph so in ordinary 

 conversation we distinguish the flower from the 

 foliage-shoot. But if we examine them both we 

 find that they have many features in common. In 

 both there is a stem, which bears appendages. More- 



