56 ME. NEWPORT ON THE NATURAL HISTORY ■ 



to learn whether it would ultimately recover from its injuries, the 

 larva seemed perfectly disconsolate, turning its head about with 

 extended mandibles in every direction, and watching like a dog at 

 fault. A second snail was then supplied to it, which I shall 

 designate 



No. 2. — This also was a snail of the very largest size and perfect 

 health. The instant it had left its shell and began to crawl freely 

 along, the larva attacked it : it was bitten once in the inferior horn 

 of the right side and immediately drew itself within the shell, but 

 almost as quickly came forth again, though it did not protrude the 

 horn. In a few minutes the snail had regained its full power of 

 locomotion, and crawled slowly along, yet apparently in agony. The 

 larva then ran quickly backwards and forwards at the side of its 

 victim, with its head and mandibles extended, and watching for a 

 proper opportunity to strike it again : it next passed backwards to 

 the side of the snail as this creature crawled forwards, and sud- 

 denly struck it again in the under lip . The snail instantly retracted, 

 and before the larva could disengage itself, drew it within the shell 

 for a short distance ; but this was evidently accidental, as the latter 

 let go its hold, and, affixed by its prolegs, awaited the onward move- 

 ment of the snail again. After this it gave its victim another severe 

 wound, and the snail withdrew itself entirely. The larva appeared 

 to search eagerly about for its lost victim, first in one direction 

 and then in another. Soon after this it bit the snail within the 

 shell, and this wound had the effect of occasioning the creature to 

 protrude itself, and again it crawled along, the larva following in 

 its track. 



Observing how little injurious effect was produced on the snail 

 by these repeated attacks of its assailant, I began to suspect that 

 if the injury to the snail depended on the effect of any specific 

 poison injected into the wound at the moment of striking it, that 

 by the repetition of attacks on the snail No. 1, the virulence of 

 the poison might have become exhausted, and the bites on this 

 one therefore produce but little injury. Accordingly I removed 

 this larva, and placed a second one in its stead to attack the snail, 

 and certainly the result which followed the bites of this second 

 seemed in some measure to justify the supposition. No sooner 

 had this larva been placed near the snail than it struck it repeatedly 

 in the head, the snail retracting at each attack, and appearing to 

 suffer much more severely than from all the attacks of its first 

 assailant : each wound appeared to be equally severe, until at last 

 the snail shrunk into its shell. It did not appear, however, to be 



