84 ( September, 



these larvae, you may find many in various stages o£ development,: 



and, by comparison, we may safely assume three or four years the' 



maximum time to attain to pupa and perfect state. 



The larvae are soft, fleshy, and of a light drab colour, with a 



small black spot upon each segment, six small feet, and the head dark 



brown ; to assist them in their work of feeding, they have upon each i 



segment a tubercle that helps them to press against the side of the 



gallery within which they are feeding ; these galleries diverge in 



various directions towards the outer edge of the solid wood, and 



towards autumn those larvae that are full-fed have approached close ' 



to the bark, and make for themselves a chamber, change to pupae, and ' 



remain in that state about three weeks, and then assume the perfect 



condition. 



5, King's Parade, Cambridge : 

 August, 1887. 



[Mr. Brown has sent us a portion of a much decayed oak branch, 

 showing the larval gallery and the pupal chamber, in which is the 

 perfect insect. — Eds.] 



The great abundance of the Cabbage- White Butter/lies {Pier Is brassicce and 

 rapes) in England in July and August, 1887- — This has become so notorious to every 

 observer that we take it to be useless to insert special notices of the phcenomenon. 

 To some of us it requires the memory to be taxed to the extent of nearly 40 years 

 in order to realize a parallel. And the extreme abundance of P. brassicce is quite on 

 a par with that of P. rapes. P. napi we do not specially allude to, but its numbers 

 seem to have been far greater than is usual. 



The cold and comparatively dry winter, and the hot summer, have no doubt 

 had some influence ; but in regarding individuals of both P. brassiccB and P. rapcB, 

 a very considerable proportion of the whole are in' a battered condition. This 

 might be due to the pugnacious instincts of the butterflies ; but there were no indi- 

 cations last year to lead us to anticipate an abundance such as the present. We 

 think it most probable that extensive immigration has taken place, and possibly in a 

 nearly continuous manner, the heat, absence of high winds, and even the drought, 

 seem to have been especially favourable for migration in these species, for the records 

 of their migrations almost invariably allude to them as occumng in calm hot 

 weather with a smooth sea. The effect on our crops of coleworts is much dreaded 

 by some. At present we prefer to regard it as an unknown quantity. Analogous 

 superabundances have often left only the most transient traces of their effects. 



But if we do not think it necessary to insert special notices on the subject of the 

 present abundance for the South of England, and even for the Midlands (for we 

 learn that the insects are equally abundant there), we shall be glad to have records 

 of a negative nature for the South, and positive information as to how far north in 

 these islands the phcenomenon has extended ; and also, generally, for Ireland. It is 

 an extremely interesting subject, and one that has several bearings. — Editoes : 

 London, August, 1887. 



