xliv 
Prof. Westwood added that Mr. Holdsworth had mistaken the Asiatic Actias 
Selene for the North American A. Luna: the larva of the Indian species was figured 
in the fifth volume of the Society’s ‘ Transactions’ (pl. v.), from a drawing by Captain 
Hutton: it was desirable to see the perfect insect, as there appeared to be several local 
races of it. 
Prof. Westwood exhibited a series of specimens of Liparis dispar, reared from the 
egg-state by Mr. Briggs, of St. John’s College, Oxford, illustrating not only a 
remarkable variation, according to the nature of the food of the larve, but also 
showing a strong tendency to degeneration. ‘The progenitors of these specimens, two 
or three generations back, had been obtained wild in Yorkshire, and were of moderate 
size (not so large, however, as the specimens formerly taken in such quantities at 
Whittlesea Mere). The eggs were received in October, 1865, and the caterpillars 
hatched during the first half of the following May. The caterpillars were divided into 
two groups, those composing one of which were fed exclusively un elm, and the others 
exclusively on whitethorn. The caterpillars spun up between the 5th and 18th of 
July. No perceptible variation was observed in the larve, cocoons, or pupe of the two 
divisions. The males in both divisions began to hatch on the 18th of July, but the 
females did not appear until half the males were already hatched. Almost all the 
males in both divisions were fully developed, only two cripples appearing out of the 
thirty-two fed upon elm. The males fed on elm averaged one inch and five-twelfths in 
the expansion of their fore wings: they were uniformly coloured, much darker and 
richer than the males fed on the whitethorn, the dark markings on the fore wings were 
strongly defined, the ground colour of these wings was also darker; the hind wings 
were reddish brown. The males fed on the hawthorn were considerably smaller, 
averaging only one inch and two-twelfths in expanse; the ground colour of all their 
wings was paler and grayer than in the others, but the markings of the fore wings 
were generally well defined. A few of the males in each division were considerably 
smaller than the specimens exhibited. In the elm-fed females fourteen out of sixteen 
were crippled, with their wings not properly developed, and even the other two were 
slightly crippled: they were not so large as those of the hawthorn-fed larva. Having 
been impregnated by the males, none of these females deposited eggs, although they 
pulled off the down from their tails and fixed it in tufts in the box, after the manner 
adopted by ordinary females of this species in the act of oviposition. Of the white- 
thorn-fed females less than one half were crippled, and these were not generally so 
much crippled as the elm-fed females. This experiment seemed to prove that had 
the species depended solely on the existence of the elm-fed individuals it would have 
become extinct; whilst the smaller size of the males of the hawthorn-fed group 
showed that even amongst them (the females of which were so much better developed 
than the elin-fed ones) the principle of degeneration had set in, and that it would have 
been very improbable that a distinct phytophagic race or sub-species would have been 
effectually produced. 
Mr. M‘Lachlan remarked that Liparis dispar was scarcely a fair subject on which 
to experimentalize and theorize, inasmuch as it now existed in this country only ina 
semi-domesticated state. 
Mr. Bates, referring to the discussion which had taken place at the previous Meeting 
(ante, p. xl.) respecting mimetic resemblances, introduced Mr. T. Belt, the gentle- 
man who had favoured*him with many of the facts, as to the aversion of inscctivorous 
