592 Notes in 1887 upon lepidopterous larve, dc. 
meaning of the method of locomotion becomes clear. 
Lepidopterous larve can walk on the under surface of 
leaves because of the presence of projecting veins, but 
the upper surface is smooth, and affords no foothold. 
Hence larve often spin a foothold upon the upper 
surface (young Cerura vinula, &c.), while the vast 
majority rest upon the under surface; although this 
is chiefly due to the more perfect concealment which 
is thus rendered possible. There is, however, a method 
by which small larve, which weigh little, can walk 
freely over the smooth upper side of a leaf: that is 
by the substitution of adherence by a sticky surface, for 
adherence by clasping. The motion of the larva is 
brought about by the same movements in both cases ; 
the larval body, or part of it, is thrown into undulations, 
which bring the anterior clasping legs in the one case, 
and the anterior part of the sticky surface in the other, 
within reach of new parts of the object over which the 
larva is walking; while the posterior claspers, and the 
posterior part of the sticky surface are simultaneously 
withdrawn from a corresponding length of the object. The 
motion being thus essentially the same, the conversion of 
the one method into the other would offer little difficulty. 
The larve, doubtless, first walked with adhesive claspers, 
and these would gradually become shorter and broader, 
thus yielding increased support by extending the area by 
means of which they adhered. Finally, the claspers 
would be altogether lost, and the whole of the ventral 
surface, from which they formerly projected, would take 
part in locomotion. 
Such is a probable history of this method of pro- 
eression, but its use appears to be beyond doubt: it is 
to enable the larve to move freely over the smooth upper 
surface of the leaves, and thus to assume their charac- 
teristic position. 
My only experience of the larva of Limacodes testudo 
is founded on an examination of the prepared specimens 
in the collection which Lord Walsingham has generously 
presented to the Natural History Museum. ‘There 
seems little doubt, however, that the larve are essentially 
similar in the points here alluded to. 
10. THE PROTECTIVE RESEMBLANCES OF THE LARVE OF 
GrOMETRA PAPILIONARIA.—The “‘ seasonal adaptation ” of 
