Having some correspondence with Mr. Johnston, he anticipating the interest I naturally felt in the entomology of my former residence, informed me of some things he head taken at Hamilton which were not to be got when I was a collector there; and the seemed to me to be of so much general interest that I desired him to make a note of them for publication. So, complying with my request, he has prepared the accompanying more extended statement on the subject. What a rapid change is taking place in the condition of the country! All my familiar and delightful hunting-grounds in that locality have been “improved out of existence.” With cultivation comes a change in the flora, which produces a change in the fauna, and in the insect fauna especially. So that future collectors will be able to form no correct idea of what was to be got by what is to be had. A thought that greatly impressed me was the persistent effort that insects are continually making to spread abroad and establish themselves in fresh territory. Most of these southern butterfies seem to have great difficulty in accommodating themselves to our shorter seasons. In the case of Colias caesonia there shoule be no trouble about food plants, as one of these is Trifolium; but in the south-west it is double-brooded, and it may perish in the attempt ot produce a second brood in this latitude, and it may take many years to bring it into harmony with its environment here.