On the supposed Auditory Apparatus of Culex. 349 
Jacq., and Falcaria Rivint, Host, also belong to this genus, 
and perhaps the Anguillula secalis, Nitschke, which lives in 
the lower internodes of the rye*. 
Almost all the species placed in this genus live in plants, 
and are for the most part gall-producers ; for, according to 
Davaine’s investigations, the cockled grains of wheat are not 
diseased seeds, but galls probably originating from the rudi- 
ment of a filament, as he found the aborted pistil in the 
diseased flowers; and Bastian (/. c. p. 87) further adduces, in 
support of this view, the fact that in his inoculation experiments 
the cockled grains were always formed on the diseased plants 
when the healthy stalks first began to Hower. By analogy 
the little sacs in the flowers of grasses in which Steinbuch 
found the above-mentioned grass-Anguillulee will also probably 
be not deformed fruits, but galls. 
As the Anguillula of the milfoil differs from the other 
species of the genus Ty/lenchus by several constant characters, 
I describe it as a new species under the name of Tylenchus 
millefolit. The following is its diagnosis :— 
Tylenchus millefolit}, n. sp. 
Albidus, transparens, corpore in utroque sexu 0°9-1°3 millim. 
longo, extremitate antica parum attenuata, obtusa, rotundata, 
postica lentius acuminata, cauda maris (a pene) 5!;—-7! cor- 
poris equante, dorsum versus hamuli instar curvata, cauda 
femine (a vulva) $ corporis equante, ventrem versus paulo 
ineurva. Distantia bulbi cesophagi ab ore latitudinem cor- 
poris eodem loco vix sequante. 
Habitaculum: Galle in foliis Achillee millefolit. 
XLVL—Lxperiments on the supposed Auditory Apparatus of 
the Culex mosquito. By Atrrep M. Mayer. 
Oum states in his proposition that the ear experiences a 
simple sound only when it receives a pendulum-vibration, and 
that it decomposes any other periodic motion of the air into a 
series of pendulum-vibrations, to each of which corresponds the 
sensation of a simple sound. Helmboltz, fully persuaded of the 
truth of this proposition, and seeing its intimate connexion 
* ¢Verhandl. zool.-bot. Gesellsch. in Wien,’ Bd. xviii. p. 901. 
+ [The worm is figured, with some details by the author (/. e. pl. i. B) ; 
but we have not thought it necessary to reproduce the figures, as the 
description is clear enough without them.—Ep. | 
¢ From the ‘Philosophical Magazine,’ ser. 4, vol. xlviii. No. 519. 
