HOMES OF SOCIAL INSECTS. 345 



moths or other enemies of any size. It is strange that the inte- 

 rior surface of the nest is provided with tubercles, a circumstance 

 that must put the insects to the trouble of gnawing them away 

 each time they add a stage. Probably the same material is again 

 employed in establishing fresh cells and in building the new plat- 

 form. 



A longitudinal section shows the peculiar disposition of the 

 combs. Just as in the spherical nests of Polybia, the highest ones 

 are perfect or almost perfect spheres; but this method of con- 

 struction is soon found to be too laborious. A nearly globular 

 mass of the brown paperlike substance exists at the top the nu- 

 cleus, so to speak. The first combs closely surround this, so that 

 they form the best parts of hollow spheres ; then come great arcs 

 of circles, followed in regular order by other tiers, their rotundity 

 becoming gradually reduced until the curve of the lower ones is 

 extremely shallow, exactly like the tiers of Tatua, except that 

 they exhibit a trifling convexity on their lower surfaces. They 

 are carried to the common wall and thereto affixed, small spaces 

 being left open here and there between their edges and the en- 

 velope. The solid wall at the top is of great thickness (see Fig. 5). 



In the nest in the British Museum already described, a quan- 

 tity of brownish-red honey was found in the upper combs, but 

 hard and dry. Even so long ago as the beginning of the century, 

 Azara, a Spanish officer, who was sent out by his Government to 

 Paraguay to make certain investigations in that country, men- 

 tions that a South American wasp which he calls chiguana has 

 the strange habit of hoarding honey. The chiguana of Azara, it 

 would seem, is identical with Polybia scutellaris. At the time of 

 publication Azara's statement was not believed, so opposed was 

 the habit that he claimed for this insect to the known actions of 

 wasps. He and his men ate from the chiguana's store, and it 

 proved deleterious. St. Hilaire, a subsequent traveler, speaks of 

 two South American honey wasps. The honey of one was white 

 and innocuous, that of the other was reddish brown and poison- 

 ous. The good honey was in an oval, light-colored nest of thin, 

 papery material, totally different from the paper of Myrapetra, 

 and was observed by Hilaire on a small bush near Uruguay, at a 

 distance of only about a foot from the ground. This wasp has 

 been described as lecheguana. Probably under the term leche- 

 guana, or chiguana, as Azara has it, the inhabitants of America 

 confound many wasps of similar kinds, and it is rather a generic 

 title for all honey wasps than for one species in particular. 



VOL. XLV. 27 



