On the supposed Auditory Apparatus q/'Culcx. 349 



Jacq., ami Falcaria liioini, Host, also belong to this genus, 

 and perhaps the Angaillala secalis, Xitschke, whieli lives in 

 the lower intcriioiles of the rye*. 



Almost all the speeies 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 })istil in the 

 diseased flowers ; and Bastian {I. 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 flower. By analogy 

 the little sacs in the flowers of grasses in which Steinbuch 

 found the above-mentioned grass-Anguillulte will also probably 

 be not deformed fruits, but galls. 



As the Anguillula of the milfoil differs from the other 

 species of the genus I'ylenchus by several constant characters, 

 I describe it as a new species under the name of Tylenchus 

 inillefohi. The following is its diagnosis : — 



Tylenchus millefolii'\^ 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) -tf^tV ^^^~ 

 poris a^quantc, dorsum versus hamuli instar curvata, cauda 

 feminiB (a vulva) ^ corporis ie([uante, ventrem versus paulo 

 incurva. Distantia bulbi oesophagi ab ore latltudinera cor- 

 poris eodem loco vix asquante. 



Habitaculum '. Gallfe in foliis Achillece miUefolii. 



XLVI. — Experiments on the supposed Auditory Apparatus of 

 the Culex mosquito. By Alfred M. MayekJ. 



Ohm states in his proposition that the ear experiences a 

 sinijjle 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. Helmholtz, fully persuaded of the 

 truth of this proposition, and seeing its intimate connexion 



• ' Verliandl. zool.-bot. Gesellscb. iu Wien/ Bd. xviii. p. 901. 



t [The worm is fi<^ed, with some details by the author (/. c. pi. i. b) ; 

 but we have not thought it necessary to reproduce the flgures, as the 

 description is clear enough without them. — Ed.] 



t Irom the 'Philosophical Magazine,' ser. 4, vol. xlviii. No. 310. 



