PHYTOLOGY, 



SCOTTISH GALLS. 

 By J. W. II. TRAIL, M.A., M.D., F.L.S. 



HELIANTHEMUM VULGARE, Gartn.— (/;) I have this 

 autumn found on this plant, on Scotston Moor near 

 Aberdeen, galls of a mite (P/iytoptus) affecting the tip or apical 

 half of the shoot. The mites seem to attack the young buds, 

 causing the leaves to remain short and crowded, while numerous 

 buds form but remain small. The epidermis of leaves and 

 branches alike becomes covered with grey hairs, while the epi- 

 dermal cells contain pink contents, frequently giving a pink 

 tinge to the gall. The deformity is similar in its nature to the 

 woolly galls so frequent on the Thyme (T. serpylluni), as also 

 to the earlier stages of the "witch-knots" on Birch. The indi- 

 vidual buds do not exceed one-fifth inch in diameter, though all 

 the buds on a shoot may be attacked, so that the whole mass may 

 be considerably larger. The gall described by me formerly (' Sc. 

 Nat.,' ii. p. 31), though somewhat like the above, is readily distin- 

 tinguished by its appearance ; and, as pointed out by Hardy 

 ('Ann. Mag. Nat. Hist.,' 1850, p. 187), is the work of a midge, 

 which he named Cecidomyia helianthemi. 



The mite-gall has been found in Switzerland, and is described 

 by Dr Thomas (Giebel's ' Zeitschrift,' 1872, vol. xxxix. p. 469), 

 but he has not met with the midge-gall, and hence suggests that 

 they are not distinct, but that the midge larvae are inquilines. 

 the mites being the gall makers. Dr Fr. Loew also has found 

 the mite-galls in Lower Austria (' Verh. Z00L Bot. Gesellschaft,' 

 Wien, 1879, vol. xxix. p. 721). 



Prunus padus, L. — (a) I some years ago (' Sc. Nat ,' i. p. 

 124), described shortly "nail-galls" (formed by a species of 

 Phyptoptus) on the leaves. I have met with these galls in many 

 localities ; they seem to be abundant wherever the plant occurs, 

 and have been frequently mentioned by German authors. 



(b) Another mite-gall, also the work of Phytoptus sp., occurs 



