British oak galls / by Edward T. Connold.

  • Edward Thomas Connold
Date:
1908
Catalogue details

Licence: In copyright

Credit: British oak galls / by Edward T. Connold. Source: Wellcome Collection.

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    also in the number, length, and depth of the furrows. Some examples are quite smooth, and but for the absence of the sharp pointed apex peculiar to the galls of Andricus nudus, many small specimens might pass as that species. Yet mature galls of A. quadri- linecttus often show a papilla when dry; A. nndus, however, never attains the same dimensions. Considerable indecision appears to have existed amongst writers as to the identity of this gall when it was first noticed on the continent. Its great varia- bility doubtless accounts for this, and it also affords an explanation of its many synonyms, to which Schenck unnecessarily contributed five. Some years it appears in great profusion, clusters of eight and ten galls being frequently found on a cat- kin stalk. A very fine example I found in 1907 con- sisted of fifteen galls upon one stalk within a length of 23 mm. “ Notwithstanding that this gall is very abundant it is by no means easy to rear the fly. From the majority of the galls parasites are usually obtained; then the larva in a large number of instances does not develop into the imago for two years ” (‘ Alternating Generations,’ p. 91). Aphilothrix radicis, Fabricius. (Plates XXYI, XXX, div. A.) Cynips radicis, Fabr., Hartig, Schenck, Kalt., Marshall; Apliilo- thrix radicis, Mayr, Adler, Licht., Fitch, Walker, Miiller; Anidricus radicis, Mayr, Cameron, Mosley. English name of gall.—“ The Truffle Gall.” Position of gall.—On exposed roots, base of trunk and branches growing therefrom. Manner of growth.—Glabrous, sessile, solitary, conglomerated. Colours. -Cream, pink, orange, red, reddish-brown. Average dimensions of a mature specimen.—Height, 45 mm.; length, 60 mm. ; breadth, 40 mm. May be sought during any month of the year. Growth is complete by the end of the second autumn. The typical condition of the gall is plurilocular, but unilarval. Usual number of cells, about sixty.
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