284 BRITISH LEPIDOPTERA. 



in wing-expanse from 4|-ins. — 7jins. Sharp says (Insects, ii., pp. 

 372 — 373): " Coscinocera hercules, inhabiting North Australians a huge 

 moth which, with its expanded wings and the long tails thereof, 

 covers a space of about 70 square inches. One of the striking 

 features of the family is the occurrence in numerous forms of re- 

 markable transparent spaces on the wings ; these window-like areas 

 usually occur in the middle of the wing, and form a most remarkable 

 contrast to the rest of the surface, which is very densely scaled. In 

 Attacus these attain a large size ; in other species such as the South 

 African India delegorguei, there is a small letter-like, or symboliform, 

 transparent mark towards the tip of each front wing ; in the genus 

 Automeris, and in other forms, instead of transparent spaces, there are 

 large and staring ocellate marks or eyes, which are concealed when the 

 insect is reposing ; in Arceina, Copiopteryx, Eudaemonia and others, the 

 hindwings are prolonged into very long tails, perhaps exceeding in 

 length those of any other moths." The sexes are usually very distinct and 

 differentiated, the secondary sexual characters often strongly marked, 

 especially in the direction of size, shape of the wings, and antennal 

 structure. These differences are, in some families at least, possibly 

 to be explained by the difference of the habits of the sexes of the 

 same species, the males, usually seeking actively for the females, often 

 flying swiftly by day, whilst the females fly slowly by night, and then 

 only for the purposes of oviposition. We find usually in the males 

 of such species well pectinated antennae and smaller but strong wings, 

 the wings of the female are usually larger in order to carry the heavy 

 abdomen full of eggs, but there are strong indications of (?) degeneration 

 in the antennae. They usually fly slowly (compared with the rapid 

 flight of the male), and frequently their powers of flight are still more 

 reduced when, as is the habit of some species, they lay their eggs all 

 in one or at most two or three batches, e.g., Saturnia pavonia. Weismann 

 states {Essays on Heredity, 1889, pp. 17, 18) that the females of Aglia 

 tau deposit all their eggs in one spot, being unable to fly owing to the 

 weight of the abdomen ; the males on the other hand fly swiftly 

 seeking the females. Poulton, however, points out [Ext. Morph. Lep. 

 Pupa, p. 252) that flight, although sluggish, is still necessary, except 

 under certain conditions, since there would be a two-fold danger in 

 depositing all the eggs in one place— that of insufficiency of food and 

 easy detection by enemies — and the latter applies to small as well as 

 large moths, but while further degeneration is thus rigidly prevented 

 in most cases, there are certain moths (in other groups — Notoloplius, 

 &c.) which escape from the limiting conditions. 



Sharp draws attention (Insects, ii., p. 372) to the ocellated spots 

 on the hindwings of the species of the genus Automeris, and Barrett 

 notes (Can. Ent., xxxii., p. 235) that these markings would appear 

 to have a protective value, as all the species with which he is ac- 

 quainted have the habit, when disturbed, of raising their primaries, 

 so as to expose the large glaring eyes, and holding the secondaries 

 at "present arms" until the fright is over. Kellogg states (Taxonomic 

 value of scales of lepidoptera, p. 68) that the sharpness of colour 

 markings depends largely on the specialisation of the scales, and 

 observes that, when sharply separated colour markings do occur in 

 lower forms, there is a specialisation of the scales within the limits 

 of the colour spots or lines much beyond the general condition of 



