40 Flowers and their Unbidden Guests. 



plants as are exposed to their attacks when grown 

 in a garden, though protected against them v[\ the 

 natural wild condition. They place the pots, in which 

 the plants to he protected are grown, on other pots 

 turned npside down, and these latter are put in a basin 

 filled with water, so as to stand about a finger's breadth 

 above the water-level. The plants are thus placed 

 as it were upon an island, and by this isolation in the 

 midst of water are well insured against molestation by 

 creeping insects. 



Whether the gardeners in thus acting are only 

 imitating arrangements which they have noticed as 

 existing in nature may be doubtful. This much, how- 

 ever, is certain, that not a few flowers when growing 

 wild are most perfectly protected against creeping 

 insects by a similar method. We find very striking 

 examples of this among the Bromeliacese. In some 

 of these (Billbergia, Tillandsia, ^chmea, Lamprococcus) 

 the rigid leaves are set in rosettes, and are more or 

 less concave on their upper surface. Now each leaf is 

 in such close contact with the two above it by the 

 margins of its concavity as to form a funnel-shaped 

 receptacle ; and in these receptacles rain and dew not 

 only collect,- but are retained for a considerable period. 

 In other species there is but one rosette, formed by the 

 collective radical leaves. This forms a single large 

 central basin, which wOl retain any water that gets 

 into it. The peduncle of the inflorescence springs 



