Tlie Life Histoni of Drilvs flavesccns. 41 



Helicella caniiana, Montaou ; Hygrcmia rvfescens. Pennant ; 



Viirm ccUaria, Mliller; Hdix nemcralis, Linne ; and even 



the largest examples of Helix aqicrsa, Midler ; passing 



indifferently from one to another in the course of its 



growth. 



When a snail is found, the larva raises itself at once 

 on to the shell and examines it carefully, assuring itself 

 of the presence of its occupant. If unsuited to the size 

 of the larva, the snail is left and the search resumed. If 

 it is satisfactory, the larva (more especially in its earlier 

 stages at least) then proceeds to sound the surroundings, 

 reachinof out to its full lenorth and rancjino; about on all 

 sides above and below, but retaining all the while its hold 

 on the shell bj' means of the anal clasping-organ. This 

 is done with a view to secreting the snail before attacking 

 it. If the position is found to afford sufficient cover, the 

 snail is soon pushed or dragged into it, till out of sight; 

 otherwise, if it is too much exposed (as on a roadway, for 

 example), the larva endeavours to remove it to a better 

 one. This removal of the snail to a place of hiding may 

 prove a difficult matter, and remarkable perseverance is 

 often shown in the endeavour to accomplish it. The larva 

 takes a firm anal grip on the outer surface of the shell, 

 and bending over the side, plants its head on the ground 

 beneath ; then, taking hold of the ground with its man- 

 dibles, it proceeds to "punt" the snail backwards over 

 the ground, so far as possible in a straight line. Where 

 an obstruction occurs, in the endeavour to pass it, the 

 larva will often raise the snail entirely into the air and 

 throw it forward bodily, but never losing its hold upon the 

 shell. If in the meantime the snail appears and attempts 

 to crawl away it is attacked with the mandibles and 

 driven back. From time to time the larva returns to 

 the summit of the shell to try the surroundings as before, 

 afterwards going back to its task, which, if no cover should 

 be found, may often be continued for an hour, or, as I 

 have once noticed, for as much as three hours before the 

 snail is attacked. It is advisable, when feeding the larva, 

 to provide some loosely placed moss, into which it will 

 soon cany the snail out of sight. In the case of larger 

 larva^ (about 14 nmi. and over) the snail is generally 

 attacked very soon, without any attempt to remove it, 

 however exposed the position may be. Larger snails (and 

 I refer especially to H. cctJitiana) seem instinctively to 



