198 Structure of Plants. 



and chionodoxa (Glory of the Snow) possess curious little 

 tubercles or appendages which seem useless. The Hepatica 

 achenes have also a little oily secretion where they break away 

 from the axis. 



The Busy Ant. 



But Dr Weiss has recently shown that those seeds and the 

 Hepatica fruits are distributed by ants, which apparently like 

 these fleshy little appendages or the oily matter of the Hepatica. 

 This distribution by ants is of real importance to the plants. In 

 three hours he saw 216 seeds brought to a nest, and one was 

 carried over 70 yards. Indeed it is quite possible that the snow- 

 drop is not indigenous in this country, except, perhaps, in a very 

 few places, simply because we are relatively deficient in ants. 

 These are by no means the only seeds carried by ants. Mignon- 

 ette, luzula, chelidonium, cow-wheat, and violet seers are carried 

 bv these insects. There is a strange little fleshy ridge at the base ■ 

 of the fruits of centaurea Cyanus which is also explained by che 

 fact that ants carry its seeds. The white deadnettle has a strange 

 habit of continuing to secrete honey whilst the fruit is ripening 

 and after the petals have fallen off. Honey attracts bees to the 

 flowers, and it would at first seem to be unjustifiable extravagance 

 for lamium album to go on forming honey when no insects are 

 re(]uired. But Dr Sernander watched lamium album, and found 

 that ants did visit the calyx, and one of them carried away a 

 millet. So that lamium album is not a waster. Other cases of 

 extra-floral nectaries or honey secretion outside the flowers have 

 also been explained simply by considering the ants. The rubber 

 trees of the Amazon valley (Hevea) possess twin honey glands on 

 the leaflet bases. The budscales, which are modified leaves, also 

 possess honey glands. It has been found that the fierce soldier 

 ants, which are justly respected all through Brazil, frequent the 

 buds for this honey, and so protect the young foliage in its most 

 dangerous period ; by the time that the budscales have fallen off 

 the mature leaves are secreting honey. This point is of some 

 practical importance to planters in Africa and the East Indies, 

 where there mav be leaf-eating insects and no soldier-ants. 



