The Scottish Naturalist. 157 



woolly stuff, among which are several reddish dipterous 

 larvae. 



Achillea ptarmica L. — (a) This gall in origin and appear- 

 ance much resembles the last, but is of a reddish grey-col- 

 our. It is terminal, and sometimes is nearly concealed by 

 a tuft of leaves. Internally are many small cells among 

 woolly substance, in each of which is a reddish larva of Ceci- 

 domyia floricola Winnering. This gall is common in Aber- 

 deenshire, (b) Seems to be an abortive leaf. There are 

 usually from two to six on the stalk among the terminal 

 leaves. They are sessile, about ^-inch long, and ovate. 

 The surface is smooth and reddish, or slightly greenish. 

 Each contains one reddish dipterous larva. Rather scarce, 

 November. 



Achillea millefolium L. — (a) Resembles (a) on A. ptarmica 

 closely in every respect. Not uncommon, (b) The gall is 

 axillary, sessile, and usually rather low on the stem. In 

 shape it is rounded or irregular, length l /% to ^-inch. The 

 surface is smooth, glossy, and green or brown. Each con- 

 tains one white larva, and splits open above when the larva 

 is ready to emerge. In one locality near Old Aberdeen 

 these galls are abundant. 



Hieracium boreale Fries. — Gall consists of a swelling on the 

 stem, either terminal or at a node ; sometimes the swelling 

 occurs on the peduncles near the flower-head. The size 

 varies much, in some cases being small and hardly percepti- 

 ble, in other cases very large, some being even if£ inch in 

 diameter. The average size is from % to ^-inch in diam- 

 eter. The shape may be rounded, spindle shape, or irregular ; 

 the surface smooth or covered closely with greyish hairs ; 

 and the colour green, or purplish. Internally it is very 

 hard and woody, and contains a variable number of cells, 

 in each of which is one white hymenopterous larva. Rather 

 common along the Dee at Banchory. 



Campanula rotundifolia L. — (a) Galls axillary or forming 

 a terminal cluster, sessile and not over i-5th-inch in diam- 

 eter. Each seems to be an abortive flower-bud. They are 

 globular or somewhat flask-shaped ; smooth, green, and 



