The Scottish Naturalist, 215 



mites [Phytoptiis). The hairs seem always to occur only on the 

 lower surface of the leaf, sunk in a rather deep hollow, corre- 

 sponding to which the upper surface is convex, and usually 

 becomes yellowish-red in colour. These galls seem frequently 

 to occur on the same leaves with the well-known Rhytistna acer- 

 intim. Their occurrence in Scotland has already been noted by 

 Greville ('Edin. Phil. Journ.,' vi. 73, PI. ii., fig. 6), and Hooker 

 (' Fl. Scot.,' ii. 34). I have found them at Inverurie and at 

 Stonehaven. 



Prunus avium, L. — The leaves at the tips of young branches 

 are frequently attacked near Aberdeen by Aphides {Myzus cerasi, 

 Fab.), which, by their suction, alter the leaves so greatly that 

 they may almost be regarded as gall makers. The leaves do not 

 attain their full size, but become curled up and distorted ; while, 

 apparently owing to excessive development of cellular tissue, 

 resulting from the constant stimulus, swellings project from the 

 upper surface corresponding to recesses on the lower surface in 

 which the insects live. 



RiBES RUBRUM, L., and R. nigrum, L., are subject to attacks 

 similar in their effects to those just described, but more notice- 

 able, as the raised parts on the upper surface generally become 

 bright red in colour. The leaves seem but little retarded in their 

 growth as a rule, but can hardly be of much service to the plant. 

 Probably the pseudo-galls are familiar to all who take an interest 

 in gardening. The insects agree well with the descriptions and 

 figures of Rhopalosiphiitn ribis (Buckton's ' Brit. Aph.,' ii. p. 9, 

 PI. 39). Another species — viz., Myzus ribis (Buckton's 'Brit. Aph.,' 

 i. pp. 180-182, PI. 34, figs. 1-4), is also abundant at Aberdeen 

 throughout the summer on R. rubriim and on R. grossidaria ; 

 but I have not noticed that it produces effects like those de- 

 scribed, though said to do so by Mr Buckton. 



LoNiCERA Periclymenum, L. — The leaves are attacked by a 

 species of Fhytoptus, which forms a pseudo-gall { = Legnoii cris- 

 pimi, Bremi). Round the whole or part of the leaf runs a 

 furrow, separated from the margin by a border of unaltered 

 tissue, usually extremely narrow, but occasionally about % inch 

 in breadth. The furrow is open along the upper surface, and 

 corresponds to a ridge on the lower surface about -jV inch deep 

 and broad. The surface of the gall is marked with fine wrinkles, 

 rendering its outline wavy ; but otherwise it differs little in aspect 

 from the leaf, and hence the galls are by no means conspicuous. 

 Where they occur, almost every leaf on a branch is often attacked. 



