On a Structure in the Antennæ of Beetles of the Chrysomelid Genus Agetocera.
- 1A figure of one of the beetles concerned is given, and their distribution and the number of known species are stated.
- 2The general structure of the antennae is described.
- 3The eighth and ninth or the ninth and tenth segments are enlarged and variously modified in the males, and these modifications are described.
- 4In most species there is an external orifice situated in a specialized surface leading to an internal tubular system in the enlarged segment.
- 5Two types of tubular system are distinguished. In the one there is a long tapering tube from which ramify in all directions tubules which are imbedded in the surrounding cellular tissue. These tubules do not rebranch again. In the other there is a larger, many branched tube, from which smaller tubules branch and rebranch in various ways.
- 6These tube-systems are in varying degrees of sclerotization; probably it varies in each individual.
- 7The form of the enlarged segments and the type of the internal tubular arrangement are constant in a given species.
- 8The crisis in the male antenna affects the basal segments more than it does the apical, and owing to this the approximate equality of the Iengths of the male and female antennz is maintained.
- 9Probably the function of these internal structures is the dispersal of the products of secretion in relation to some aspect of sex activity.
- 10A new species of this genus is described and figured.