Montlily Microscopical"! 
Journal, Sept. 1, 1869. J 
PROCEEDINGS OF SOCIETIES. 
175 
purpose of determining the possession of a distinctive scale by the 
males, several facts, some well known, others opposed to generally- 
received opinions, and others perhaps of a novel character, had forced 
themselves upon his notice. As was well known, the Lepidoptera in pass- 
ing from the egg to the mature state, underwent the several changes of 
larva, pupa, and imago. In two, and in some cases in only one of these, 
did the insect partake of food. For while all were voracious in the 
larval state, and while many possessed a proboscis of great length, 
other species did not possess any suctorial apparatus, and therefore 
could not take food. The parent, as a rule, laid the eggs on or near 
the food-substance of the larvae, the gradual development of which, in 
many transparent eggs, can be watched under the microscope. While 
the changes are taking place the colour of the egg also changes. As 
soon as the larva is ready to escape, it eats its way seldom at the 
apex or micropyle, where some writers assert it always escapes, but 
generally below and at one side. The eggs of many are very beautiful 
objects for the microscope. The larvae of various, and some of pecu- 
liar forms and habits spend their time in eating and changing their 
skins. In fact, the chief aim of their existence, at this stage, is 
storing up vitality to enable them to undergo their further changes ; 
for when supplied with insufficient food, or alternately starved and 
fed, the imago stage is either not reached, or a mutilated or deformed 
insect results. When the time arrives for the change to the proper 
state, some construct elaborate cocoons, others susj^end themselves 
from twigs, &c., others burrow, all casting the last larval coat, when 
they become chrysalides. Just before the final change, the colour 
of the chrysalis alters, and through the pupa-case the several parts of 
the future insect may be made out. At last the pupa-case bursts, 
and the /w%-fledged insect emerges, with wings of minute size ; these 
expand as air and fluid are forced through them. The scales at the 
time of emerging are all of full size. This is an important fact, for 
some assert that the scales expand together with the wing membrane 
itself, the air breathed-in, entering between the laminae of each scale ; 
others maintain that the scales are small and few in number in newly- 
developed insects, but larger and more numerous as the insect advances 
in age. Both these theories are contrary to fact. If either that 
portion of the pupa-case which covers the wings be removed a few 
days before an insect emerges, or the wing of a newly-emerged insect 
be taken, it will be seen that the scales are all of full size, but closely 
packed together longitudinally and laterally. As the wing membrane 
expands they are drawn wider and farther apart, until they present 
the appearance seen on a fully-expanded wing. Experiments made 
with the Puss moth and Oak eggur, to determine in the first case by 
what means the insect dissolved its hard cocoon, and in the second 
to find how the males were attracted, were next described. Several 
cases of parthenogenesis, in which none of the larvae reached the third 
moult, and examples of a second copulation, were next mentioned. 
The females possessed greater vitality than the males, and made, in 
articulo mortis, efforts to lay their eggs, which in some cases for days 
after death were extruded. While such varied colours were seen in 
Lepidoptera, the scales themselves, when viewed by transmitted light 
