322 The Scottish Naturalist. 



the lobes remain crowded together, with the margins at 

 the base slightly involute and fleshy ; and between them 

 live several white larvse of Cecidomyia. These can 

 spring a distance of two or three inches. The galled 

 leaves are yellowish-green. I have found them at the 

 end of June near Aberdeen and near Stonehaven. (T.A., 

 L, 64.) 



Scabiosa SUCCisa (Devil's-bit Scabious), Mr. Binnie (B.I., 161) 

 states that Mr. Cameron informed him that he had 

 found on this plant at Cadder, near Glasgow, an axillary 

 gall much like that found on Achillea Millefolium, pre- 

 sumably the gall of a species of Cecidomyia. 



Centaurea nigra (Black Knapweed) has the ovaries galled by 

 Trypeta solstitialis L. The galls are irregularly ovate, 

 about T 7 g- by -f\ inch, woody and hard, brownish, but 

 covered with short pale hairs. A small opening above 

 gives entrance to a cavity occupied by the larva. The 

 galled flower-heads are unchanged externally, though 

 each contains one, two, or more galls often united into 

 a mass. They are most easily detected by squeezing, 

 the heads between the finger and thumb. They occur at 

 Banchory on Deeside ; and Dr. White has sent them to 

 me from Dunkeld. Though local, they are abundant 

 where they occur. The flies are easily reared from the 

 galls. (TS.N, IV., 15-16 ; T.A., L, 64.) 



Achillea Ptarmica (Sneezewort). 1. Galls of llormomyio 

 Ptarmico3 Vail. (H. floricola Winn.) are common in 

 autumn in Aberdeenshire and Kincardineshire, and Mr. 

 Binnie records them as common near Glasgow. They 

 form a rounded mass of abortive flowers, \ to J inch 

 across, reddish-grey and woolly, and surrounded with a 

 circle of leaves. They are formed of soft tissue, among 

 which are small cavities, each occupied by one range 

 larva. 



2. Another form of gall on this plant may also belong to H. 

 Ptarmica. It seems to be an abortive leaf-bud or leaf. 

 Usually several occur in the axils of the leaves near the 

 tip of the stem. They are ovate, acute, about | inch 

 long, sessile, reddish-brown or greenish. Each contains 



