306 WHEELER— ANT LARV^. 



swollen and rounded and embracing the sides of the head. These 

 evidently correspond to the single prothoracic pair of the Tetra- 

 poiicra tessmanni larva. The mesothoracic segment has a pair of 

 smaller appendages nearer the mid-ventral line. Between them 

 arises a very peculiar organ with a swollen, pear-shaped base pro- 

 longed into a slender, apparently erectile, tentacle-like process which 

 extends up in front of the head and terminates in a small ampulla. 

 The first abdominal segment bears a pair of large swollen appen- 

 dages lying at the base of the mesothoracic pair and united with a 

 large and very prominent mid-ventral tubercle. This tubercle and 

 its lateral appendages are represented in the T. tessmanni larva but 

 the others, with the exception of the third prothoracic pair, are ab- 

 sent. Sections and stained, cleared preparations of the whole larva 

 show that the various tubercles contain portions of the fatbody, at 

 least in the bases of their cavities, and next to the hypodermis a 

 dense, granular substance, evidently a coagulated liquid produced 

 by the underlying adipocytes, or trophocytes. The same liquid also 

 fills the unpaired tentacle, except its pear-shaped base, which con- 

 tains fat cells. Around the bases of the tubercles are muscles so 

 arranged that their contraction must increase the pressure on the fat 

 and granular liquid and in all probabilit}- cause the latter to exude 

 through the hypodermis and delicate chitinous cuticle onto the sur- 

 face. The whole arrangement of the tubercles, in fact, constitutes a 

 system of exudate organs, or exudatoria, as I shall call them, 

 adapted to secrete substances that can be licked up by the ants when 

 they are feeding and caring for the larvse. In this stage the man- 

 dibles are small, soft, blunt and unchitinized so that the larva must 

 be fed with regurgitated liquid food. The labium has a peculiar 

 pair of fleshy appendages, shown just beneath the mandibles in yA. 

 The body is naked, except for a few sparse, pointed bristles on the 

 dorsal surface and the median pair of prothoracic appendages. As 

 nothing like this larval stage is known among ants or indeed among 

 the Hymenoptera, I propose to call it the " trophidium." 



The second stage larva is shown in Fig. 8^. The various exuda- 

 toria are smaller in proportion to the remainder of the body but are 

 still much like those of the trophidium. The body is more elliptical, 

 the mandibles are more pointed and distinctly falcate, but even in 



