LEPIDOPTERA. SLS 
(fig. 95.3. head of Pap. Machaon sideways, with the spiral maxillze 
partly unfolded; 95. 4. c, base of maxilla ; 95. 5. f, labium; g, base of 
labial palpus, and d, rudimental maxillary palpus at the base of the 
maxille ; 95. 6. labium detached, with one of the labial palpi). Some 
Lepidoptera, however, take no food in the perfect state, and their 
mouth organs are accordingly almost atrophied; this especially takes 
place amongst the Bombycide, where, as in fig. 105. 2., the maxillee 
(one of which, the left, is alone represented) are so much reduced in 
length as to be useless, although the labial palpi (fig. 105. 1. 3.) are 
of considerable size (their place of insertion in /ig. 2. is indicated by 
the two ovals at the base of the maxille). In the Hepiali, however 
(fig. 104. 12.) the labial palpi are even obsolete, and in the emperor 
moth (fig. 105.4.), the mouth organs are only indicated by minute 
fleshy tubercles arranged in a circular space in the middle of the 
under side of the head. In the genus Aglossa, as the name implies, 
the mouth is described (but erroneously) as being obsolete. Cor- 
responding variations of course occur in the development of the 
digestive organs of the imago: thus, in some of the typical Sphin- 
gid in which the spiral apparatus attains its greatest length, 
nearly equalling that of the entire body, the stomach is scarcely 
smaller than it is in the pupa state (Newport, in Phil. Trans. 
1834, vol. xiv. figs. 12, -13. ¢e, d.); whereas, in the Dendrolimus 
pini, in which the parts of the mouth are atrophied, with the 
exception of the labial palpi, the stomach is almost obsolete. 
(Suckow, Anat. Physiol. Untersuch. tab. 2. f. 10.6.) Of the lower 
parts of the mouth, the labial palpi are those which are most rarely 
effaced: next to these are to be mentioned the maxille themselves ; 
the maxillary palpi being often obsolete, even when the maxillz are 
at their highest state of development. Thus in Papilio Machaon, 
Cynthia cardui, and Sphinx celerio, these palpi are scarcely discern- 
ible; whereas in Zygzna scabiosz they are more distinct (fig. 103. 
10.), and still more strongly in Galleria, Crambus, and some other 
of the minute Lepidoptera. (Savigny, Mém. sur les Anim. sans Ver- 
tebres, fasc. 1. pl. 1, 2,3.) In Lampronia, Euplocamus, and some others 
figured by Curtis, they are still more elongated, considerably exceed- 
ing the maxille themselves in length. 
The thorax is robust and compact, the prothoracic portion minute, 
owing to the fore legs performing no supplemental functions, whilst 
the mesothorax, to which is attached the anterior pair of large wings, 
