40S WILLIAM M. MANN 



frequently as the immature stages, possibly because the drop is 

 harder to get at on account of the wings. One adult was stroked 

 for some time by an ant and failed to respond, but a half minute 

 later when the ant had gone it spontaneously ejected a large 

 drop, which was found and lapped up by another ant. 



Enslin placed specimens of both the immature and mature 

 phases of the tree-hopper in the immediate vicinity of a cinerea 

 nest. Sometimes an ant received a drop of secretion from the 

 Homopteron and went on its way. Others took the insect in 

 their mandibles and attempted to take it into the nest, some- 

 times successfully. At other times the insect struggled too 

 much. The fate of those taken into the nest was not observed. 

 Without access to its food plant the insect could not secrete 

 the liquid for which the ants attend them; besides, those which 

 Enslin kept without food died within two days. It may be that 

 those adults brought in after copulation deposit eggs in the 

 nest, but nothing definite regarding this is known. In fact, 

 only scant observations on the relations between any Mem- 

 bracids and ants have been recorded. 



Escherich (24) in Ceylon studied the " myrmecophilous " plant 

 Humboldtia, the stems of which have hollow internodes, each 

 with an opening at the tipper end. The leaves are provided 

 with nectaries that afford a food supply to ants, several species 

 of which nest in the hollows, and Schimper had considered the 

 plant typically myrmecophilous. Escherich found that only a 

 small percentage of the internodes were used as nesting sites by 

 ants, and that these were species which nest in various other 

 places also. Unless the twigs were violently shaken the ants 

 made no attempt to defend the plant. Many of the occupied 

 stems showed scars made by woodpeckers attracted to the 

 ants, so Escherich concludes that the relationship between 

 plant and ant is in no wise symbiotic, but rather parasitic, as 

 the latter derives its shelter and food from the former, giving 

 no service in return, and even being directly harmful through 

 attracting enemies. Escherich believes that records of symbiosis 

 based on the study of the plant structure only, without observa- 

 tions on actual relationships, are not worthy of consideration. 



In Abyssinia Escherich observed the foraging habits of a 

 species of Messor. During the day the ants remained in the nest. 

 At nightfall they emerged, leaving the nest by a distinct trail 



