1847.] Linnean Society. 353 



Ab U. diantka quacum maxime affinis difFert pedicellis teretibus nee mar- 

 ginatis, calcare ascendente labio longiore nee descendente, lobis calycinis 

 in fructu noti auctis antherisque non eonstrictis. An seniina U. dianthce 

 alata ? 



Utricularia fasciculata, vide DC, no, 8, p. 18. no. 18, adde : — Plaeenta 

 globosa spongiosa, seminibus compressis raarginatis rugosulis uno la- 

 tere foveolato altero prominulo. 



A further communication, from a letter written by Mr. Edge- 

 worth, dated Banda, 30th August, 1847, was made to the meeting, 

 respecting a remarkable effect produced by the leaves of Gymnema 

 sylvestris, R. Br., upon the sense of taste, in reference to diminish- 

 ing the perception of saccharine flavours. 



Read also a paper " On the Formation and Use of the Air- Sacs 

 and Dilated Tracheae in Insects." By G. Newport, Esq., F.R.S,, 

 F.L.S. &c. &c. 



The paper was commenced with the remark, that the presence of 

 air-sacs in insects is known to every comparative anatomist. These 

 sacs are largest and most numerous in the Hymenoptera, Lepidoptera 

 and Diptera. They are numerous and capacious in the Dragon-flies 

 among the Neuroptera, but are smaller and fewer in the Ephemera, 

 the Sialidce and the Scorpion-flies. In the Coleoptera they exist only 

 in the volant species ; and even in the same tribe, as in the Cara- 

 bidcB, they are found in the winged, but not in the apterous species. 

 In all insects in which they occur they are largest and most nume- 

 rous in the swiftest and most powerful individuals. They are found 

 in the Orthoptera only in the migratory families ; while in those 

 which are truly saltatorial insects the tracheae are enlarged in some 

 parts of their course, but are not to be regarded as properly saccu- 

 lated, and sacs are never found in the larva state of any species of 

 insect. The sacs are formed by the dilatation of tracheae during the 

 metamorphoses of the insects, which commences at the close of the 

 larva state, when the insect has ceased to feed. This dilatation goes 

 on for the first few days only in those species which hybernate, and 

 is resumed again in the spring, but it continues uninterruptedly to 

 the development of the perfect insect in those which change to that 

 state in the summer. 



The author showed that the longitudinal trachere of the third and 

 fourth segments of the larva of winged insects give off a small branch 

 at the sides of each segment, which, divided into two portions, passes 

 outwards and " is involved in a fold of the new tegument that is 



