186 Transactions. — Zoology. 



white and a black insect from the pupa in a stormy and cold 

 chmbite, such as we have in the alpine regions. A passing gleam 

 of sunshine w^ould enable the black insect to dry its wings, fly 

 away, and propagate its species before the white one was nearly 

 developed, and consequently there would be a continual selec- 

 tion in favour of the darkest varieties. This theory, I believe, 

 is the true explanation of the singular prevalence of melanic 

 species at high elevations, and may, of course, be equally well 

 applied to those dark varieties and species of insects which 

 have hitherto been almost invariably taken in the arctic 

 regions. That there is a marked tendency to a darker colora- 

 tion in the Leindoptcra from the Mount Arthur district as we 

 ascend in altitude, I do not think any one can for a moment 

 dispute who examines the representative collection now before 

 the Society. 



I must refer those wishing to learn further particulars in 

 connection with this most interesting subject to the abstract 

 of Lord Walsingham's paper contained in the "Entomologist," 

 vol. xviii., page 81. 



In conclusion, I should like to give a very striking instance 

 of protective colouring which I obsei'ved when on a previous 

 visit to the Table-land in 1888. While gathering some small 

 branches from a birch -tree I discovered a beautifully-variegated 

 larva, imitating exactly the delicate hues of the lichen-covered 

 twigs. After feeding on the birch-leaves for a few days it spun 

 up, and emerged as a very grey form of Declana floccosa on the 

 7th June. I have often seen the larva of this insect, as before 

 mentioned ("Trans. N.Z. Inst.," 1888, p. 190), round Welling- 

 ton, where, however, it does not in the least resemble the curious 

 caterpillar found on the Table-land. This circumstance, I 

 think, gives us a hint as to the means by which alpine insects 

 may have assumed some of tlieir peculiarities. 



In connection with my previous visit to the Table-land in 

 1888 I should also mention that it was three weeks later in 

 the year than in 1889, and I noticed great differences in the 

 insects observed : for instance, in February, 1888, Stathmonyma 

 anccps was very abundant, Erehia lyluto scarce, Rhyssa anti- 

 podum one taken and three or four seen, Gladopais mints 

 very common. In January, 1889, I found S. ancejJS was rare, 

 E. pJuto very abundant, and of 11. antipodum and Gladopais 

 viirus I neither saw nor captured a single specimen. This, 

 shows that there is a rapid successioir of insect-life on the 

 mountains, wliich can only be properly studied by numerous 

 and prolonged visits of entomologists. 



