24 
great “ livornica ” year was in 1870, when my late friend Mr. T. Sturt 
took one (now in my cabinet), and saw several at Mount Edgcombe, 
Cornwall. Another uncertain visitor, although not a rarity, which 
has been more than usually abundant, is Herse convolvuli. This has 
turned up all over the Kingdom and as far north as Moray. There 
appears to have been a succession of immigrants of this species, for 
many were taken in August in a worn condition, and those recorded 
in September are stated to have been in fine condition. 
We are used to the varying numbers of those species we consider to 
be immigrants, such as H. convolvuli, Colios edusa, Colias hyale, 
even Pyrameis cardui and others, and we attribute their varying numbers 
year to the influx or otherwise of foreigners ; but the same phenomenon 
is observable, as to the abundance or scarcity, of species which ai'e un¬ 
doubtedly indigenous and as far as we know are not given to migration. 
For instance, last year, Notolojduis antiqua appeared to be unusually 
abundant, and I have also known a decided Triphaena pronuba year, and 
not to mention Xylena monoylypha. Ayrotis exclamationis and others 
equally hardy and common, each species being in unusual profusion in 
different years. It is often difficult to account for the uTiusual abundance 
of a certain insect, as however bad the season may be generally, some 
species thrive when all others are nearly exterminated. I might 
mention two other interesting captures during the year, one being Nola 
centonalis, at Wocdbridge, in a moth trap, and the other being Nola 
albulalis, near Weymouth, which also came to light. The last 
mentioned species has always been looked upon as confined to N. Kent, 
but as there is nothing in its focdplant, or the nature of the ground on 
which it is found to account for it being so local, it may yet be in 
abundance in other places, although still undiscovered. 
Perhaps I may be allowed to depart from the collectors stand point of 
entomology, and even at the risk of getting out of my depth, enlarge on a 
few of the thoughts that have come to my mind while breeding larvae 
during the season. In the paper I read on Stauropns fagi, some few years 
ago, 1 ventured some remarks connected with an experiment in breeding 
that insect. The result of the experiment being, that the larvae 
corresponded in colour to artificial environment, which, to my mind 
seemed to justify the opinion that the similarity to environment could 
not be brought about by Natural Selection, as the influence of heredity 
played no part in the result. I was told afterwards by a very prominent 
scientist that I was perfectly wrong, and in fact the points noticed 
were simply the essence of Natural Selection. Now', gentlemen, I am 
going to be bold enough to stick to my colours. 
The examples that I have before me now are from the larvae of 
Pacltys bctularia. The facts regarding them are w’ell known to most 
entomologists, although to seme it may be new. From the batch of 
eggs laid this spring from one female I had a large number of larvae, a 
portion of which I fed from the commencement on sallow', and these 
larvae all assumed a light green colour. A second portion of the same 
batch I fed on fcirch fiom the commencement, and these all assumed a 
dark brown colour. The other surroundings of the larvae were similar 
in each case, both being brought up in glass cylinders. The colour of 
the larvae in each case was obviously protective, as they all assimilated 
to the food plant to a remarkable degree, the green ones to the leaves 
and stalks of the sallow, and the brown ones resembling the twigs 
rather than the leaves of the birch. 
