62 WILD FLOWER FAMILIES 



encloses the rounded mass of the spadix, which is 

 completely covered by the florets, in which the pis- 

 tils mature before the stamens. The pollen is 

 shed in great abundance in the closed chamber 

 of the spathe, so that it may easily be carried to 

 other plants through the visits of insects, though 

 evidently it is so protected from the wind that 

 there is little likelihood of its being blown from 

 plant to plant. 



Many plants call insects to their aid in this 

 work of pollen distribution. One would think, 

 however, that this early flowering Swamp Cab- 

 bage had little chance of such assistance at a 

 season when the northern slopes are yet covered 

 with snow and the sheltered pools are still filled 

 with ice. But the plant has brought about a 

 marvellous adaptation to the conditions of its life. 

 At this early season certain small flies are abun- 

 dant in the situations where the Swamp Cabbage 

 grows. They fly about in the early spring sun- 

 shine and when the weather is cold and stormy 

 they seek such shelter as may be at hand. Now 

 the most perfect shelter that these flies can find is 

 inside the Swamp Cabbage spathes, which are so 

 constructed that neither rain nor wind may enter; 

 and, surprising as it may seem, the blossom not 

 only furnishes shelter from the elements, but it 

 also provides artificial heat. Botanists have 

 found that the purple substance of the spathes 



