''DEFENCE, NOT DEFIANCE. 159 



efforts simply resulted in the production of new 

 fissures in the epiderm, and fresh discharges of 

 milky juice, so that the position of the ants became 

 each moment worse and worse. Many of them now 

 tried to escape by getting, as best they might, to 

 the edge of the leaf and letting themselves fall from 

 thence to the ground. Some succeeded, but others 

 tried this method of escape too late ; for the air 

 soon hardened the milky juice into a tough brown 

 substance ; and after this all the strugglings of the 

 ants to free themselves from the viscid matter were 

 in vain. Their movements became gradually fewer 

 and weaker, until finally they ceased altogether, and 

 the dead animals were left adhering to the involucre 

 or the uppermost leaves." 



The milky juices of the Poppy {Papaver som- 

 niferitui), which soon hardens into opium when the 

 capsule is artificially scratched, is an illustration of 

 the origin and natural function of similar defensive 

 secretions, not necessarily provided against ants, 

 with which other plants have gradually and success- 

 fully armed themselves. 



