1910.] 59 



sont placees bien singulierement, elles sont aiix bouts extremement 

 fins de corues tres fines. Ces memes cornes avec dequelles le formi- 

 caleo perce un insecte, et avec lesquelles il le tient saissi, sont chacune 

 un corps de pompe. Au moyen de ces deux corps de pompe il fait 

 passer dans ces intestins toute la substance du malheureux, que est 

 devenu sa proie. Nos lions des pucerons, ou nos petits lions, ont de 

 semblables cornes, avec lesquelles ils sucent les pucerons.* 



Von Grleichen tried in vain to reconcile his observations on this 

 point with those of Reaumur, and he had almost equal difficulty in 

 finding another mouth opening. Between the mandibles and palpi he 

 saw nothing but a surface of very fine horizontal folds, and it was 

 only when he seized a larva by the head with his forceps and brought 

 it under a lens that he noticed in the fore part of the head an opening 

 which could be notliing but the movith. As he observes that this 

 mouth is only used for sucking, its perfect closure is a natural con- 

 sequence, as is also the impossibility of opening and seeing it unless 

 by a properly directed pressure of the head. 



When the larva has reached the age of 13 or 14 days, it leaves 

 the scenes of its bloodthirsty activity and seeks to conceal itself in 

 some angle of a twig or on another leaf. Up to that time it seems to 

 have made no use of its spinneret (which is placed at the end of the 

 body), but within half-an-hour it has covered itself within a web. 

 This web is white in colour, fibrous and tangled like wool. It is not 

 too close to prevent the enclosed larva from being seen in a cun^ed 

 position, the head almost withdrawn within the thorax. The cocoon 

 consists of two separate layers, the one as above described, but the 

 inner is hard as if made of dried paste (Kleister) : this inner layer 

 might be described as a perforated capsule rather than a web. 



So far Von Grleichen. He reared two of the flies in July about 

 the fourth week after the lai-vse had spun up, but he failed to observe 

 the actual emergence — a misfortune which the observations of Standfuss 

 have made good. 



Since the foregoing was written, I have received through the 

 medium of my friend. Dr. Eis, an extract made by Professor Standfuss 

 from his unpublished notes on the biology of Brepanepteryyc . I am 

 very much indebted to Professor Standfuss for this, and as his notes 

 are so i\\\\ of interest, I venture with his permission to give a transla- 

 tion of them. 



* See Sharp, Cambridge Natural History, vol. v, pp. 4.55-7, as to the mouth parts of ant 

 lions. It is tliere explained how the mandibles and thie lobes of the maxilLB are modified, 

 and co-adapted to form sucking organs. 



