The Scottish Naturalist. 



229 



myself met with them I had not occasion to refer to 

 them in my earlier papers. However, specimens were 

 sent me in May, 1889, by Dr. Robertson from Errol in 

 Perthshire. The appearance of the infested buds is 

 well shown in Murray's "Economic Entomology" (1877, 

 P- 355) m a woodcut. The bushes frequently suffer 

 very severe injuries from this pest, which it is next to 

 impossible to extirpate except by rooting out and burn- 

 ing the plants. I have not met with any record of the 

 occurrence of this gall on the Continent of Europe. 

 Oentaurea Scabiosa L. Along the footpath at the top of 

 Kincraig Cliffs, near Elie in Fife, I found in August of 

 the present year, numerous examples of galls of a mite 

 (Phytoptus) on the leaves, especially on those growing 

 close to the ground. On some of the weaker stems and 

 branches almost every leaf bore the galls, many leaves 

 being more or less covered by them. They are like 

 blisters in the leaf-tissue, scattered over the surface with- 

 out any definite order, and often two or more are fused 

 together more or less completely. The individual galls 

 are usually circular in outline, \ to 2\ mm. across, and 

 lenticular in section, which seldom equals 1 mm. At 

 first they are pale yellowish-green, but this changes into 

 a rusty or dull purplish brown, becoming dark brown 

 after the death of the tissues. On the upper surface 

 there is usually a paler patch of thin epiderm, perforated 

 by a hole for the entrance or exit of the mites. These 

 are generally few, and live among the loosely grouped 

 cells of the mesophyll, which is the part most altered by 

 the suction of the mites. This gall is very similar to the 

 blister galls of Phytoptus in the pinnae of the Mountain 

 Ash, that are so common in many localities of Scotland. 



Dr. Thomas records the galls on C. Scabiosa (/. c. y p. 

 266) from Upper Bavaria, at 730 metres (about 2400 ft.) 

 above the sea ; but I find no other mention of their 

 occurrence. 



Salix. I am indebted to the kindness of Dr. White for galls on 

 various species of this difficult genus, as already re- 

 corded in my papers above referred to on the Gall- 

 making Hymenoptera and Diptera of Scotland. In so 



