CHAP. CIV. BETVhA^CEM. i/ETULA. 1703 



Russia, where whole tracts of forests of ditFerent kinds of trees occur, there 

 is scarcely any tree more frequently struck by lightning than the birch ; which, 

 he says, refutes the superstitious notion of the Laplanders, who, believing 

 that the tree is never struck by lightning, seek for shelter under its branches 

 in a thunder-storm. It has constantly been observed, he says, that the birch 

 is always struck by the electric fluid transervely, below the top, and shivered 

 to pieces ; while the pine is ploughed by a deep furrow from the apex to the 

 ground, tearing oft' the bark, and leaving the tree entire. The common birch, 

 Mr. Westwood observes, is a tree upon which a very great number of insects 

 feed, seldom, however, causing any mischief of importance. Of these, it will be 

 sufficient to notice a few of the more remarkable ; indicating by a star those 

 which not only feed on the birch, but on various other trees ; and by a dagger 

 those which feed on the birch only ; commencing with the Lepidoptera, the 

 caterpillars of which, either exclusively or partially, subsist upon its leaves. 

 Amongst the butterflies, the Camberwell beauty (Vaness« Antiopa) is a 

 partial birch-feeder, whilst the brown hair-streak butterfly (Thcclrt betulae) 

 seems to be confined to birch woods ; appearing in the winged state in the 

 month of August. Amongst the Sphingida; Smerinthus tllise (the lime hawk 

 moth) occasionally feeds upon the birch. Amongst the Linnajan ^ombyces, 

 the singular lobster caterpillar (Stauropus fagi) partially feeds upon this tree, 

 and is met with, though but rarely, at Birch Wood, in Kent. * Leiocampa 

 dictEe'a and *L. dictsciides, * Lophopteryx camelina, *L. carmelita, * Ptilo- 

 phora variegata, *E'ndromis versicolor (the rare glory of Kent moth), the 

 reputed British species *Aglaia tau, *Eriogaster lanestris, *Callim6rpha 

 miniata, * Lithosia quadra. Amongst the A'octuidae, * Apatela /eporina, 

 *Acronycta auricoma, f Ceropacha fluctuosa, *C. flavicornis (the caterpillar 

 of which is a leaf-roller), * Cosmia trapetzina, f C. fulvago, * Brepha notha, 



* Catocala fraxini. Amongst the Geometridee, * Hybernia capreolaria, 



* H. prosapiaria, * H, defoliana, * Phigaha pilosiiria, * Bisto?i prodromarius, 

 *B. betularius, *Hipparchus ^xipilionarius, +Cabera exanthemata, f Mela- 

 nippe hastata, f Emmelesia heparata. Amongst the smaller moths, fPla- 

 typteryx /acertula, * Drepana falcataria, * D. ungufcula, * Pyralis barbalis, 

 f Antithesia betuletana, f Anacampsis betulea, ^geri« spheciformis (one of 

 the small clear-winged hawk moths), and Zeuzera aj'sculi (Jjg. 636. in p. 887.), 

 feed upon the wood of the birch. The coleopterous insects, Balaninus 

 betulEe, Deportius betulee, Rhynchites betulae, and Chrysomela betulas, also 

 feed upon the birch in the larva state, and are found upon it when they have 

 attained their imago form, devouring the tender leaves and young shoots. 

 Several species of renthredinidte, or saw flies, also feed upon the leaves 

 whilst larvae, including Selandria betuleti, and Lyda betulae. The little flat 

 hemipterous insect A'radus betulas resides beneath 1'553 

 the bark, whilst A^phis betulae. Coccus betulae, and --^^^.^^-^ 

 Psylla betulae subsist upon the young shoots and 

 buds. When the birch begins to deca}', various fungi 

 root themselves into its wood. The principal of these 

 are Daedalea ^etulina Fries (ylgaricus ietulinus L., 

 and our/g. 1553.), Polvporus 6etulinus Fries (boletus hetiilmus BiiJL t. 312.), 

 and P. versicolor Fr. (ourfg. 1354.); of these, P. ietulinus generally grows 

 on the trunks of dead trees, and has white flesh, which has an acid taste 

 and smell. The epidermis is very thin and delicate, and easily 1-554.^ 

 peels off; when dry the whole plant is very light, and its tex- 

 ture is between coriaceous and corky. (F/ig. Fl., v. p. 140.) 

 Polyporus fomentarius (see Q. i?6bur) and P. nigricans Fries 

 are also found on the birch. The latter, though called the 

 black amadou, is quite unfit for making tinder. It is a very 

 distinct species, and is of a bright shining black, though, when 

 old, the epidermis becomes cracked, and of a dull ash colour. 

 Radulum orbiculare Fr. El., 1. p. 149. (i/ydnum radula Fries 

 Syst. Mjis., 1. p. 423.; H. spathulatum Grev. Fl. Edin., p. 406.) is found on 

 the trunks of dead birches. Plilebia radiata Fries grows on the living birch 



