174 



Aquatic liitt 



again, either by creeping or otherwise. 

 The return to the surface requires a long 

 observation, as it remains feeding a con- 

 siderable time. Apparently this is an 

 instinctive habit and interference is re- 

 sented. If the fallen snail is lightly 

 touched it will discharge some air, and, 

 if irritated to the extent of complete dis- 

 charge, it will at once creep to the sur- 

 face for a renewal. I was fortunately 

 able, a few days ago, to observe a speci- 

 men of corneus in its second year, gently 

 drop about nine or ten inches below the 

 water surface or half the depth of the 

 tank. It came to a momentary halt, and 

 then floated back to the surface. In this 

 instance, there was no interference in 

 any way, and the snail had no assistance 

 from a spun thread. This is the only 

 case I have seen, although I have for 

 years carefully watched the progress of 

 every falling animal presenting the op- 

 portunity for observation. This is an 

 important fact to record, as I have long 

 thought corneus possessed some such 

 power, as a fallen snail on reaching the 

 bottom, often has some trouble to attach 

 itself, and this act of corneus is particu- 

 larly interesting to witness. This, and 

 many other observations, are better seen 

 with snails that have been in confine- 

 ment a long time and have overcome 

 their natural nervousness. Many snails 

 observed .whilst creeping from the bot- 

 tom to the surface will, if gently detach- 

 ed when well on the journey, at once rise 

 to the surface, but this experiment is 

 the most successful with those which are 

 educated to being frequently handled. 



I regret I have never been able to sat- 

 isfactorily ascertain the age a snail may 

 reach, as most of my attempts have been 

 more 01 less upset by the attentions of 

 Cypris, nor have I been able to observe 

 the number of eggs a snail may actually 

 produce for the same reason. Two speci- 



mens of corneus, two years old, under 

 observation from the first to the twenty- 

 second of July this year, laid twenty-two 

 batches of eggs, but when hatching began 

 it confused further count. 



The statement that freshwater snails 

 are in the habit of creeping out of the 

 water and on doing so die, is frequently 

 met with in books dealing with the uni- 

 valves, and observers are warned to pro- 

 vide covers for their tanks. This pre- 

 caution is unnecessary if reasonable care 

 is taken to keep the captives under prop- 

 er conditions. A freshwater snail is a 

 somewhat intelligent creature, and is 

 capable of acquiring knowledge apart 

 from mere instinct, and erratic move- 

 ments on the part of the creature can 

 only be interpreted in one way — ignor- 

 ance is no excuse for cruelty. Aquar- 

 ium keepers, no doubt, have had the mis- 

 fortune to find a newly-introduced fish 

 dead or dying, having leapt from its new 

 home. The common minnow affords a 

 good illustration. If this fish is put into 

 a new home it is quite common for it to 

 jump out, especially during the first 

 night, evidently seeking its old quarters. 

 If the tank is covered, in most cases for 

 one night only, all danger is past and 

 the fish settles down. Fish do not like 

 changes — nor do snails. If an escaped 

 snail is put back into its new home it 

 usually accepts the situation if this is not 

 impossible. When snails, which have 

 been kept for some time, are found above 

 the water line, suspicion is at once di- 

 rected to the presence of enemies or foul 

 water. 



One species, Limnaea pereger, has had 

 a name imposed upon it describing it as 

 a restless creature, and as far as I can 

 see, without just cause. Certainly, L. 

 pereger exhibits characteristics peculiar 

 to itself. It is the only freshwater snail 

 I know of which can, and does, catch 



