LETTING IN THE CITY. 155 



«ome years in a parish just outside London, which, happily, until a 

 few years ago, was neglected by the speculative builder, and which 

 retained in certain parts, almost wild corners, longer than most of the 

 surrounding parishes, I have had some opportunities of watching the 

 gradual dispersal of the Fauna and Flora, caused by the encroachment 

 of bricks and mortar into the meadows, scraps of Avoods, and odd bits of 

 no-man's land, where wild life used to flourish. 



By a reference to the old writers on British lepidoptera, we shall 

 learn that the number, both of species and of individuals, occurring 

 round London in former times, was greatly in excess of what it was in 

 the earliest times now remembered by living entomologists ; and most 

 of us, too, can remember when certain species were much more 

 abundant than they are now. 



In very early times, up till the end of the twelfth century, there 

 were extensive forests round the then small City of London (Fitz- 

 Stephen's Survey). After that date, the forests were gradually cleared 

 and turned into meadow-land. The probably still larger extent of 

 heath -land seems to have remained in its primitive condition till 

 a much later period, possibly owing to its less fertile nature. 



As the great city grew larger the population required more food, 

 and the meadow-lands were ploughed up and laid out as market- 

 gardens, and then gradually, as the city spread out in all directions, 

 the market-gardens were taken over by the builder, and shops and 

 houses were erected. This was roughly the process by which the once 

 Avild country was invaded by the city, and has ultimately become 

 acres of streets and houses (see Flora of Middlesex, Trimen and Dyer, 

 1869). 



When the forests were cleared odd bits of them were left standing 

 here and there, and to these, those butterflies which delight in sylvan 

 conditions, must have been restricted ; in these spots they, or many 

 of them, remained till entomologically historical times. Thus Albin 

 (1720) mentions Zephi/nis betulae as being rare in the larval state in 

 Hornsey Wood. Harris {Anrelian, p. 7, 1766), speaking of Apatura 

 iris, says " these flies are found in the greatest plenty at Combe Wood, 

 near Kingston-upon-Thames." Theda quereus commonly taken at 

 oak in Honour Wood, near Peckham (p. 21), and yemeobius lacina " in 

 plenty at Combe Wood " (p. 57). Lewin {Papilios of Great Britain, 

 p. 18, 1795) says of Liiuenitis sibylla, " an inhabitant of every patch of 

 wood in England." Again speaking of Melitaea athalia (op. cit., p. 

 B2) he says " common some years in June," and quotes Wilkes as 

 finding the larva in Tottenham Wood. 



All these species, as well as Leptidia sinapis, and all our species of 

 Argynnis, as we used to call them, except lathonia, which seems always 

 to have been of rare occurrence, doubtless were abundant in what is 

 now the London district, till the forests were cleared, after that they 

 became confined to certain strongholds, which, as land became of 

 greater value, were more and more diminished in size, till either they 

 became too small to hold the butterflies, or too isolated to allow of the 

 arrival of any fresh settlers, and so the then living races died out 

 by various accidents. The famous Epping Forest was never so 

 completely isolated, and remained fairly extensive, and those are, no 

 doubt, two reasons why the forest-haunting butterflies have lingered 

 .SO' long in its recesses. Mr. Main informs me that Z. hetnlae is still 



