ANT 274 



not as a protection that the leaves are wanted. 

 Once in the nest, the leaves are cut by the 

 jaws of the ants into tiny pieces, and on the 

 molding heap so formed grow fungi, the 

 favorite food of these ants. The heap is kept 

 very clean, so that no bacteria ever grow 

 upon it. 



Certain ants, particularly in the tropics, de- 

 pend on plants not only for food but for 

 dwelling places as well. The rotting stump 

 of a tree, the hollow stem of a weed, or the 

 capacious trunk of a tulip tree affords them a 

 comfortable home; but perhaps the most at- 

 tractive type of plant home is that described 

 by Thomas Belt in his Naturalist in Nica- 

 ragua. 



One low tree, very characteristic of the dry 

 savannahs, is a species of acacia, growing to a 

 height of fifteen or twenty feet. The branches 

 and trunk are covered with strong curved spines, 

 set in pairs, from which it receives the name of 

 the bull's-horn, they having a very strong re- 

 semblance to the horns of that quadruped. These 

 horns are hollow, and are tenanted by ants, that 

 make a small hole for their entrance and exit 

 near one end of the thorn, and also burrow 

 through the partition that separates the two 

 horns ; so that the one entrance serves for both. 

 Here they rear their young, and in the wet 

 season every one of the thorns is tenanted, and 

 hundreds of ants are to be seen running about, 

 especially over the young leaves. These ants 

 form a most efficient standing army for the plant, 

 which prevents not only the mammalia from 

 browsing on the leaves, but delivers it from 

 the attacks of a much more dangerous enemy 

 the leaf-cutting ants. For these services the 

 ants are not only securely housed by the plant, 

 but are provided with a bountiful supply of 

 food ; and to secure their attendance at the right 

 time and place, this food is so arranged and 

 distributed as to effect that object with won- 

 derful perfection. The leaves are bipinnate. At 

 the base of each pair of leaflets, on the midrib, 

 is a crater-formed gland, which, when the leaves 

 are young, secretes a honey-like liquid. Of this 

 the ants are very fond ; they are constantly 

 running about from one gland to another to sip 

 up the honey as it is secreted. 



But this is not all ; there is a still more won- 

 derful provision of more solid food. At the end 

 of each of the small divisions of the compound 

 leaflet there is, when the leaf first unfolds, a 

 little yellow fruit-like body united by a point at 

 its base to the end of the pinnule. Examined 

 through a microscope, this little appendage looks 

 like a golden pear. When the leaf first unfolds, 

 the little pears are not quite ripe, and the ants 

 are continually employed going from one to an- 

 other, examining them. When an ant finds one 

 sufficiently advanced, it bites the small point of 

 attachment ; then, bending down the fruit-like 

 body, it breaks it off and bears it away in 

 triumph to the nest. All the fruit-like bodies 

 do not ripen at once,- but successively, so that 

 the ants are kept about the young leaf for some 



ANT 



time after it unfolds. Thus the young loaves 

 are always guarded by tin- ants; and no cater- 

 pillar or large animal could attempt to injure 

 them without being attacked by the little war- 

 riors. The fruit-like bodies are about one-twelfth 

 of an inch long, and are about one-third of the 

 size of the ants ; so that the ant bearing one 

 away is as heavily laden as a man bearing :i 

 large bunch of plantains. I think those facts 

 show that the ants are really kept by the :u-acia 

 as a standing army, to protect its leaves from 

 the attacks of herbivorous mammals and in- 

 sects. 



Studying Ants. Many forms of animal life 

 which it is interesting to read about cannot 

 be studied at close range, but this is not true 

 of ants. With very little trouble anyone may 

 observe for himself the habits of these little 

 creatures. The materials needed are simple 



A FORMICARIUM 



A simple suggestion for a temporary home for 

 ants while they are being studied. 



an ordinary tumbler, a saucer or plate, and, 

 if possible, a small magnifying glass which may 

 be purchased for fifty cents. 



Into the tumbler put part of an ants' nest, 

 such as may be found in any open, sandy 

 stretch. The tumbler should be about half 

 full, and as many of the ant colony as possible 

 should be included. Then place the tumbler 

 in the plate or saucer and pour water around 

 it, or your ant visitors may have escaped by 



