( Cxav’'w) 
retired precipitately, doubtless owing to the discharge of an 
offensive odour or noxious fluid. Occasionally the ants fell 
down from the earthwork on to the top of the drivers and then 
beat a most hurried retreat over their backs, though the drivers 
did not seem to attempt to attack them. 
*“ These manceuvres went on for a quarter of an hour, and 
I then dropped a slightly maimed minor driver near one of 
the two ants. The ant seized it at once and anteflexed its 
abdomen; a tremendous scuffle ensued, the combatants rolling 
over and over in a confused heap. The driver then seemed to 
gain the upper hand, for the other ant started to run away 
with its opponent firmly fixed on to its leg, and no efforts on 
the part of the ant were successful in dislodging it. 
“T think the ants were on the look-out to steal pupae 
or prey from the drivers, but it is a matter I will look 
into.” 
Prof. Poulton suggested that the senses of the wounded 
Dorylus might have been blunted so that it was not susceptible 
to the defensive secretion of the Camponotus. 
5. The fly Bengalia depressa, Walk. (Calliphorinae), robbing 
Dorylus nigricans on the march.—The following notes were 
illustrated by a specimen of Bengalia depressa and the second 
series of Dorylus nigricans referred to on p. cxxill. Both were 
dated Oct. 12. The specimens illustrating the notes of later 
dates were not yet available. 
‘‘ T spent most of this Sunday morning, Oct. 12, in watching 
a column of driver ants, many carrying immature forms, on 
the march, endeavouring to find out the business of the other 
ants [Camponotus sericeus] with them. I found that some 
Diptera, insects as large as a Sarcophaga, were also concerned 
with the drivers, but I did not succeed in elucidating their 
object any better than I did the purpose of the ants. About 
eight of these Diptera were to be seen settling here and there, 
usually on an elevated object, e.g. a stone close beside the 
drivers, which, in a column about two inches broad, were 
crossing the road. Every now and again one flew up and 
poised itself on the wing immediately over the column, where- 
upon the larger soldiers assumed a threatening attitude and 
the fly retired. Sometimes a fly ran over the ant column 
