{ Ixx ) 



(Plate C, fig. 3). It is then seen to be a compact pile of 

 little transparent bubbles, which must have hardened im- 

 mediately after being ejected by the insect. It is, however, 

 though hardened, excessively fragile ; and it is diflicult to 

 believe that it could offer any physical obstruction to the 

 approach of any imaginable assailant of the feeding larva. 

 Besides which, the pillars stand far enough one from the 

 otlier to allow of a free passage between them. It has been 

 suggested to me that the so-called ' stockade ' has some 

 resemblance to various objects (fungoid growths, stalked eggs, 

 etc., etc.), and that this deceptive mimicry might serve as a 

 protection to the larva against some particular enemy. At 

 any rate, for whatever reason, the formation of this stockade 

 seems to be considered by the larva as an indispensable pre- 

 liminary to feeding. Miss E. Chawner tells me that she has 

 tried the experiment of brushing it off, and that the larva 

 then seems considerably discomposed, leaves off feeding, and 

 presently moves away elsewhere, and forms a new circle 

 before it ventures to recommence its meal. It is curious also 

 that when the hole eaten in the leaf reaches a certain size, 

 the larva reaches out and constructs a similar circle of pillars 

 on the other side of the leaf, and that when it has reached a 

 certain stage in its own growth it abandons its defensive 

 system altogether, passes to the edge of the leaf and feeds 

 there, just like the larvae of other Nematids, without any 

 visible precautions against disturbance from without. This 

 remarkable instinct, which apparently is peculiar to this 

 one species, was first observed and fully described by the 

 Dutch entomologist v. VoUenhofen (a former Hon. Fellow of 

 our Society)." 



The exhibitor then read extracts from an English transla- 

 tion (by Mr. May) of v. VoUenhofen's memoir on the subject 

 which appeared in vol. xx of the Zoologist (1862). The 

 insect is there called Nematus vallator, n.sp., its identity with 

 Fabricius's compressicornis not having been realized. It is 

 rather a pity, though it cannot be helped, that the Law of 

 Priority reduces that which in itself is certainly the more 

 suggestive and euphonious of these names to the rank of a 

 mere synonym. 



