or THE glowwoem (lampyeis noctilttca). 57 



able to remain within the shell more than a few minutes after 

 being wounded, as it seemed to writhe in agony from the bites. 

 These observations therefore do not seem to support the statement, 

 that it is usual for the larva to be drawn by the snail into its 

 shell ; on the contrary, the instinct of the larva seemed to lead it 

 to avoid this interruption to its attack, as before striking severely 

 it invariably affixed itself firmly by its prolegs and curved the 

 posterior part of its body in the form of an arch, as if for the pur- 

 pose of affording a means of support, and allowing the entire body 

 to be suddenly extended forwards to reach the object of its attack. 

 On one or two occasions, when the larva made a very fierce bite, 

 and struck its mandibles deeply into the wound as the snail was 

 crawling at full length out of its shell, the larva was dragged along 

 for a short distance, but I never saw the creature drawn into the 

 shell by the snail. I now set aside this individual like No. 1, and 

 placed a much smaller snail with the larva first employed. This I 

 shall call No. 3. The size of this snail was not greater than that 

 of a large pea. 



No. 3. — The larva bit this snail once, and the effect was imme- 

 diately evident, although this creature had so repeatedly bitten the 

 larger snail ; yet the power of locomotion was not destroyed. The 

 specimen No. 4 was next exposed to this larva : this was rather 

 larger than No. 3 : it was bitten once in the head and retired 

 within its shell. At the expiration of one minute it came out 

 again, but its power of locomotion was affected, and it was unable 

 to protrude its left horn. I now allowed this snail to be bitten 

 by another larva which had not been employed before, and which 

 was rather smaller than those before used : the snail was bitten 

 once by it and withdrew itself, and seemed to exhibit effects of 

 something more severe than the simple wound. This snail I put 

 by like the former. 



Another specimen, No. 5, was now employed : this was rather 

 larger than the two preceding, but not so large as the first two ; 

 it was also bitten once by the larva last employed. This specimen 

 as yet had been perfectly uninjured. The larva seemed voracious 

 and active ; it bit this specimen slightly at the extremity of the 

 foot, and I allowed it to bite again the head and neck. The snail, 

 when bitten on the head, instantly retired and threw out abun- 

 dance of froth ; it soon emerged from the shell, and attempted to 

 crawl, but it was unable to keep the shell upright on its back ; 

 it then retired within, and again came forth from the shell with 

 apparently a little more power. I then allowed it to be bitten 



