FACTS FOR FARMERS. A TREE THAT KEEPS A STANDING ARMY.

Waikato Times, Volume VII, Issue 370, 26 September 1874, Page 2

FACTS FOR FARMERS. A TREE THAT KEEPS A STANDING ARMY.

Among the v.iritd moms of doff nee developed C 1 by plants in tlrir ceaseless straggles foy existence t! there is, perhaps, none more wonderful or effective than that of a species of acacia which abounds on the dry savannahs of Central America. It is called t] the bulPs-hom thorn, from the strong curved 2 thorns, like bull's horns, set in pairs all over the 2 trunk and branches. These no doublt help to pro- c tect the tree from the attacks of browsing animals ; but it has more dangerous enemies in the leaf-cut- M ting ants and other insects. Against these the tree c maintains a numerous standing army, for which it t( provides snug houses stored with food, nectar to v drink and abundance of luscious fruit for dessert. * ( When first developed the thorns are soft and 5 filled with a sweetish pulp, much relished by a ? species of small springing ants, never found except * on these trees. Making a hole near the point of s one of each pair of thorns, these ants eat out the L interior, then burrow through the thin partition at * the base into the other thorn, and treat it in the ° same manner. The hollow shells thus formed make admirable dwellings, none of which are left un- 5 tenanted, as any one may discover by disturbing r the plant, when the little warriors swarm out in force and attack -the aggressor with jaws nnd stings. The leaves of the plant are two-winged, and at base of each pair of leaflets, on the mid rib, is a * gland which, when the leaf is young, secrets a ( honey-like liquid, of which the ants are very fond. c This insures their constant presence on the young 6 leaves, and their most zealous service in driving off other insects. ( A still moi-e wonderful provision of solid food is 1 made for a similar purpose. At the end of each < of the small divisions of the compound leaflet there ' grows a small, fruit-like body, which, under the ( microscope, looks like a golden pear. When the { leaf first unfolds, the little pears are not quite ripe, ' mid the ants are continually employed going from ] one to another to see how they come on. As these 1 fruit-11l c bodies — which appear to have no other I use than as ant food — do not all ripen at once, the i ants are kept about the young leaves for a consider- < able time. When an unt finds one sufficiently ad- 1 yanced, it bites the point of attachment, then, bend- j ing down the prize, breaks it off and bears it away in triumph to the nest. ' The.se ants — aspecies of pseudomynna — are found, ' as already noticed, only on these trees ; and that ! the trees leally keep them as a bodyguard seems evident from the fact that, when planted in localities where their little protectors do not exist, they ■ ars speedily defoliated by leaf-cutters, which let theni severely alone on the savannahs, while their honey glands and golden pears offer no attractions, to tio ants of the forest. Apparently, both acacias and psoudomyrmas have been mutually modified in the eoiuso of "time, until they are now quite dependent on e<ich other for suppoit and protection.