1880.] The Structure and Action of a Butterfly’s Trunk. 315 
same time the necessary stiffness. The rings are not perfectly 
regular, but vary in width and are here and there broken, or 
branch and anastomose. 
Figure 2 shows a few of their irregularities, but they are less 
apparent at the tip than higher up. With a strong magnifying 
power the rings are seen to be made up of little plates! soldered 
together, except on the front surface near the inner edge of the 
maxilla, where the plates become separated and more or less 
hexagonal. Dotted over the whole surface, but more thickly at 
the tip, are seen little circular plates with a minute transparent 
papilla in the center. These are believed to be metamorphosed 
hairs, and in some butterflies and moths become greatly and 
peculiarly developed,? and are supposed by Fritz Müller to be 
organs of the sense of taste or touch, perhaps both. Breitenbach, 
however, thinks they play the part of teeth on a saw or file, and 
serve to tear the delicate flower tissues for obtaining the sweet 
juices contained 
in them. In the 
famous orange- 
sucking moth 
( Ophideres fullon- 
ica), which some- 
times greatly 
damages the or- 
ange harvests, Mr. 
Francis Darwin? 
Fic. 3.—Transverse section of trunk showing wa two 
has descri maxille united byi me dove-tail ge snd isara the = 
scribed the or canal, c; the air tubes, ¢v; , nerve and mm, the tw 
remarkable arma- sets of muscles, probably more m ra displaced in the er 
ture at the tip of ting; these are omitted in the left maxilla. 
the trunk, which enables the moth to pierce even the thick skin 
of an orange, and one set of the curious spines in this case are 
simply our small papilla much developed and specialized. These 
! By examining Figs. 3 and 4 it will be evident that these plates are the bases of 
little pyramid-shaped bodies (in some regions more like 
stout nails or tacks) which are imbedded in, or rather special- 
ized portions of, the cuticle. Three of these are 
annexed figure, 3 B, where cu is the ae fatale laminated, 
and hy the underlying matrix or hyfoderm. It is not impro 
FIG.3.B 
e that each pyramid corresponds to a Kakie cell of the hypoderm Arch. 
€ papers by Breitenbach in Katter’s Entomol. Nachr., V, 238, and i inthe 
rig Anat., xv, 8 and xvi, 308. 
Quart, Four. Micr. Sci., XV, 385. 
