20 Inaugural Address by the President. 



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. If one of them 

 be touched or a branch shaken, the little ants {Pseudomyrma 

 btcoJor Guer.) swarm out from the hollow thorns, and attack 

 the aggressor with jaws and sting. 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 wonderful perfection. The leaves are bi-pinnate. 



At the base of each pair of leaflets, on the mid-rib, is a 

 crater-formed gland, which, when the leaves are young, secrets 

 a honey-like liquid. Of this the ants are very fond ; and 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 wonderful 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 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 another, examining them. 



When the 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-hke bodies do not ripen at once, but successively, 

 so that the ants are kept about the young leaf for sometime 

 after it unfolds. 



Thus the young leaf is always guarded by the ants ; and no 

 caterpillar or larger animal could attempt to injure them 

 without being attacked by the little warriors. These facts 



