A HISTORY OF NORFOLK 



A slight preliminary sketch of its more important features may be 

 useful. By great good fortune, records are preserved of some of the 

 more interesting species in this county from a much earlier date than in 

 most others. Thus with regard to that extraordinary species, Hypogymna 

 dispar, of which the sexes are totally unlike each other ; which has so 

 mysteriously disappeared altogether from this country, and yet by acci- 

 dental introduction to the United States of America has so devastated 

 vast tracts of woodlands that it has cost and is now costing the govern- 

 ment of that country hundreds of thousands of dollars in the struggle 

 for its extermination ; we are supplied with indubitable evidence of its 

 former abundance with us. Mr. John Curtis writes thus {British Ento- 

 mology, 1825—40) : ' It is not easy to conceive the delight I experienced 

 when a boy on finding the locality for the "Gypsy moth." After a long 

 walk I arrived at the extensive marshes of Horning in Norfolk, having no 

 other guide to the spot than the Myrica gale, and on finding the beds of 

 that shrub, which grows freely there, the gaily-coloured caterpillars first 

 caught my sight. They were in every stage of growth, some being as 

 thick as swan's quills. I also soon discovered the moths, which are so 

 different in colour as to make a tyro doubt their being partners. The 

 large loose cocoons were also very visible, and on a diligent search I found 

 bundles of eggs covered with the fine down from the abdomen of the 

 female. With eggs, caterpillars, chrysalides and moths I speedily re- 

 turned, enjoying unmixed delight in my newly-gained acquisitions.' Now, 

 although Myrica gale still flourishes in abundance at Horning there is no 

 trace of the moth, and no evidence exists as to the date or means of its 

 extinction. The Rev. T. H. Marsh however records its existence fur- 

 ther west, at Cawston, not uncommonly, till 1861. Since that date it has 

 apparently never been seen in Norfolk ; and except in most rare and 

 casual instances, not within the British Isles. 



The fens of Norfolk extending for many miles along the banks of 

 the Yare, the Bure, the Thurn and the Ant form still, with those of 

 Cambridgeshire, the sole haunts in these islands of that handsome and 

 striking butterfly the swallow-tail [Papilio machaon), a species which 

 abroad is by no means confined to fens, but flies at large in most parts of 

 Europe, even ranging over mountain districts, and in hotter regions, as in 

 Asia, especially affecting such situations. Why it should with us so 

 scrupulously attach itself to fens, hardly ever flying a mile away from 

 them, is probably an insoluble mystery. Happily the fens themselves are 

 so situated, and so extensive, that there is little risk of its extermination. 

 This advantage it shares with species of similar proclivities, such as 

 Spilosoma urticce, Arsilonche venosa, Nonagria neurica, Meliana jiammea, 

 Herminia cribralis, Schoenobius mucronellus, S. gigantellus, Peronea shepherdana, 

 P. lorquiniana, Phoxopteryx paludana, Ergatis subdecurtella, Xystophora 

 palustrella, Eaverna phragmitella, Cosmopteryx lienigiella and C. orichalcea, all 

 of which are common to the Cambridgeshire fens as well as these. This 

 protection is perhaps even more important in the cases of Lithosia muscerda, 

 Calamia brevilinea, Chilo paludellus and Sericoris doubledayana, which seem 



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