36 WEEVIL-RESISTIXG ADAPTATIONS OF COTTON. 



many of the colonies moved their nests to new burrows excavated 

 immediately at the bases of the cotton plants. In some parts of the 

 field the proportion of cotton plants having kelep nests established 

 about their roots reached nearly 75 per cent, whereas the chance 

 that the positions of the cotton plants which stood in regular rows 

 would coincide with those of kelep nests would not be one in hun- 

 dreds. 



The success of this experiment would seem to justify fully the 

 suggestions made in connection with the first announcement of the 

 discovery of weevil-resisting adaptations of the cotton plant, namely, 

 that the protection which these Central American varieties had 

 been able to secure from the kelep had afforded them an opportunity, 

 perhaps unique, of developing other resisting adaptations. The 

 Kekchi and other related cottons, though having no monopoly of 

 weevil-resisting characters, furnish, however, the only instance as 

 yet known to scientific observation in which a field culture of cotton 

 has been maintained for long periods of time under climatic condi- 

 tions favorable to the boll weevil. 



In Central America, at least, the secretion of nectar by the cotton 

 is not a useless or meaningless function, as observers of the plant in 

 other parts of the world have sometimes supposed. The cotton is 

 not the only plant upon which the kelep can live, nor the boll weevil 

 the only insect upon which it preys. To secure the attention and 

 obvious preference of the kelep the cotton has been obliged to put 

 forth the superior attractions provided by its numerous extrafloral 

 nectaries. 



This additional proof of the value and efficiency of the kelep does 

 not affect, of course, the possibility of acclimatizing it in the United 

 States. A more extended search in Guatemala resulted in finding the 

 insects under a wide range of conditions, and at altitudes of from '200 

 to 2,000 feet. It lives and thrives, moreover, in soils very much drier 

 than those to which it was supposed last year to be confined. Last 

 year's experiments in Texas indicated likewise that the kelep with- 

 stands drought much better than it does standing water in its burrows, 

 and care is being taken this season to locate colonies with a view to 

 adequate drainage. 



OTHER XECTAR-BEARING PLANTS VISITED BY THE KELEPS. 



The honey-collecting habits of the keleps are not confined to the 

 cotton. Another favorite is a species of Bidens (B. p'rfosa) called by 

 the Indians " tshubai," which has considerable value as a forage 

 plant, being of quick growth and succulent texture. 



The preference of the kelep for the tshubai as a second choice after 

 cotton was noted last year, but no explanation was found, though 



