AKTS VS. ALEXIA. 93 



^•August 27. — In the morning caterpillars dropped into the midst 

 of a very strong colony of brown stinging ants [iSolenopsis xyloni) were 

 very quickly destroyed j some of them made hardly any effort to escape. 

 The same colony was experimented on in the heat of the day, and four- 

 fifths of the caterpillars escaped. 



"August 28. — Experiments made with a colony of brown ants (aj)- 

 parently Dorymyrmex flavtis), by dropping caterpillars in the path of a 

 moving column, resulted in the escape of fifteen ; five were killed by 

 the ants. I have several times observed a column of the same species 

 of ants engaged in robbing colonies of another common species and 

 at such times they are much less inclined to attack caterpillars in their 

 path. I have never yet witnessed the capture of a cateri^illar upon 

 the plants by ants unless it had webbed up and was stiffened to form 

 pupa. During the hottest hours of the day the worms were more pow- 

 erfully affected by the sting of this brown ant, and a greater proportion 

 were captured by them at this time; a caterpillar sometimes succumbed 

 after being twice stung." 



The following extracts from Mr. Schwarz's notes are. interesting in 

 this connection : 



" Of ants only three species were actually observed to attack worms 

 or chrysalids, Dorymyrmex insanus, Solenopsis xyloniyO^ndy on a single oc- 

 casion, a small undetermined species. The first two species are very 

 common, and, in my opinion, the only ones which are of importance in 

 this Cotton Worm matter. The colonies of all these species are to be met 

 with in the cotton fields. The former are always small and consist of 

 round or oval subterranean excavations connected with the surface by 

 a single, almost vertical gallery at the entrance of which no hill of up- 

 thrown soil is raised. Solenopsis xyloni, on the other hand, very often 

 forms large colonies on places not disturbed by plowing or other causes. 

 Those in the cotton fields are usually very small, without doubt on ac- 

 count of the frequent disturbances. There is always a hill of loose soil 

 or sand, as the case may be, raised by this ant, through which several 

 entrances lead to shallow but large irregular excavations below the 

 surface of the ground. There are two or more such chambers, one above 

 the other. A Scarabaeid beetle, Euparia castanea, is inquilinous with this 

 ant, and hundreds of them occur in a large colony. Its larva is found 

 in the innermost part of the nest, and feeds upon the roots of grasses ; 

 the beetle is to be found in all parts of the nest, but rarely in young 

 colonies. 



*«As to the efScacy of these two species of ants, I wish to remark that 

 on several occasions I saw them at work destroying larvae or chrysa- 

 lides which I had every reason to supx)ose were in healthy condition 

 when attacked. In one instance I saw them attacking a moth just 

 issuing from the chrysalis. More often they attack worms which are 

 wounded or disabled by other enemies, and pupae which have been 

 stung by some Heteropteron, or which are rotten. They attack fre- 



