MIGRATION OF VARIOUS BIRDS AND INSECTS. 471 



places, for the extreme irregularity of its occurrence, is equally 

 remarkable in others, (as in some parts of the west of England, and 

 in Jersey,) for appearing with great regularity. 



A very singular circumstance is also related of the Cynthia Cardui, 

 by Mr. Knapp, in his amusing and excellent " Journal of a Natu- 

 ralist." After some other remarks on the species, he observes that 

 " some years ago a quantity of earth was raised in cutting a canal in 

 this county (Gloucestershire) ; and in the ensuing summer, on the 

 herbage that sprang up from the new soil on the bank, this butterfly 

 was found in abundance, where it had not been observed for many years 

 before." Might we not reasonably expect, if the soil about Hampstead 

 were to be turned up, on any occasion, to some depth and extent, that 

 the extraordinary and distinctly marked butterfly, Cynthia Hamp- 

 stediensis, would reappear, although so many years have now elapsed 

 since it was last seen ? 



To return to the subject of migration ; nothing is more easy, in the 

 spring, to a person acquainted with the voices of our native migratory 

 birds, than to note down the periods of their respective arrivals, as they 

 all then announce their approach by their perpetual loquacity 5 but, in 

 the autumn, it is no such easy matter to ascertain the exact time of 

 their several departures. The following observations, therefore, may 

 not be altogether without interest. The last willow- wren (Sylvia 

 melodia), which I noticed in this neighbourhood this autumn, was on 

 the 18th of September; the morning was cold and frosty, and it was 

 hopping about on a large dunghill, attracted, I believe, chiefly by the 

 warmth. The same morning I observed a blackcap (Ficedula atri- 

 capilla), and shot a babillard (F. garrula). The arrival of this last 

 bird, in the spring, was observed by Montagu (in Wiltshire) to be for 

 many years, from the 21st of April to the 10th of May. In the spring 

 of 1831, I had a nest of this species brought to me, containing four eggs, 

 so early as on the 23rd of April ; the first babillard which I noticed 

 this year was on the 6th of May. Grey fly-catchers (Muscicapa gri- 

 sola), continued plentiful here until about the 20th of September ; the 

 last I observed was on the 25th. I heard a blackcap on the 27th ; and 

 on the 26th a wryneck ( Yunx torquilla), was shot. Several ring- 

 ousels (Petrocincla merulozdes*) , appeared during the Michaelmas 

 week ; they were extremely shy, and difficult of approach. 



A species of creeper, also, hitherto undescribed, has been two or three 



* Turdus torquatus, LIN. 



