54 MB. NEWPORT ON THE NATURAL HISTORY 



seeing the difference in the results. I therefore infer that there is 

 some special poison inserted, or influence exercised, at the time of 

 striking the prey, like that of the snake-tribe ; and that the effect 

 on the snail is proportioned to its size, for it takes repeated bites 

 to kill a large one. I am further confirmed in this opinion by the 

 fact that, when a dead snail is presented, the glowworm simply 

 begins to eat slowly. The way in which the glowworms remove 

 the snail, when killed, is interesting : they walk backwards with 

 it, using the claws (prolegs) at the end of the tail as feet." 



These interesting facts, communicated to me by my friend 

 Professor Ellis, immediately led me to watch the proceedings of 

 the glowworm. I had the gratification of witnessing every parti- 

 cular, and the opportunity of confirming what he had pointed 

 out, as he had forwarded to me with the glowworms some of the 

 same species of snail as those employed by himself. These snails 

 proved to be the Helix nemoralis, and were mostly young indi- 

 viduals; but there were also some full-grown ones, and besides 

 them was a small specimen of Limax agrestis. As a general result, 

 I found that the larvae attacked most fiercely and fed upon the 

 former species of snail most voraciously, but would not touch the 

 latter ; their proper food therefore appears to be the Helices. 



On repeating these observations, I at first thought that it was 

 only the smaller snails which fell a prey to this larva, but I soon 

 found, as stated by the writer in the ' Penny Cyclopaedia,' that 

 the very largest are also destroyed by it ; for I have seen the full- 

 grown and largest-sized Helix attacked by a single larva. I have 

 not, however, seen the larva actually drawn into the shell by the 

 snail, as mentioned by M. Maille, and I therefore suspect that 

 was an accidental occurrence which is likely to happen, since the 

 mode of attack, as M. Maille states, is by sudden bites, repeated, 

 as my friend observes, at intervals, and, as I myself noticed, 

 made by the larva with apparently great caution. So far from the 

 larva being drawn into the shell by the snail, I have noticed that 

 the frothy matter that is invariably given out by the snail when 

 it returns into its shell after being bitten by its assailant, is parti- 

 cularly avoided by the larva. I witnessed the attack of a larva 

 on a very large and full-grown snail while crawling. The larva 

 raising the anterior part of its body made one sudden and very 

 cautious bite about midway in the body of the snail on the margin 

 of the foot, and repeated this by running backwards and forwards 

 from the tail to the head of the snail. At each bite the snail 

 seemed to be in great agony, and a greenish transparent fluid was 



