water snails. One of the commonest of 

 these small mollusks is the Bythinia ten- 

 taculata, the shell of which does not ex- 

 ceed half an inch in length, and is formed 

 in a graceful, tapering turret. This spe- 

 cies, like many other European animals, 

 has been introduced into this country and 

 bids fair to eclipse many of the native 

 species in the number of individuals. It 

 probably first came over with some mer- 

 chandise, which was shipped west by the 

 way of the Erie canal. The snail, once 

 established in the canal, has had every 

 opportunity to spread over the entire 

 United States. The canal is emptied 

 every year and cleaned and the water, 

 with its organisms, is allowed to flow into 

 the little streams and the larger rivers 

 and thence into Lake Ontario. From this 

 lake this species has spread so that it is 

 also found in Lakes Erie and Michigan, 

 and will eventually spread over the entire 

 northern portion of the United States. 

 This is but one of the many examples of 

 different species being carried by human 

 agencies from one part of the world to 

 another. 



But there are many species of these 

 smaller fresh-water snails that are pig- 

 mies, indeed, whose tiny shells do not 

 exceed an eight of an inch in length and 

 which require the aid of a microscope to 

 adequately study their delicate organ- 

 isms. These minute animals live on water 

 plants and on any submerged object. 

 They vary from long, pointed, steeple- 

 like shells to those which are perfectly 

 rounded like a miniature apple. In our 

 own country these little creatures may be 

 found in any of our ponds or streams, and 

 the lively little animals are well worth a 

 closer acquaintance. They are known 

 scientifically under the difficult names of 

 Paludinella, Amnicola, S'omatogyrus, 

 Fluminicola, with many others, and do 

 not bear any specific English titles. 



Much more might be written concern- 



ing the habits and variations of the fresh- 

 water snails. The best way to become 

 acquainted with these interesting ani- 

 mals is to collect them alive and study 

 their various modes of life in an aqua- 

 rium. This receptacle need not be an 

 elaborate or expensive affair. A fish 

 globe six or eight inches in diameter 

 makes an admirable aquarium and even 

 a quart Mason fruit jar has been success- 

 fully used by the writer. The bottom 

 should be covered to a depth of an inch 

 or more with clean, fine sand and several 

 stones should be introduced for the snails 

 to "roost" upon. If the aquarium is large 

 enough a few water plants like water cress 

 might be introduced to assist in purify- 

 ing the water. 



The best Mollusks for this purpose are 

 the Limnaea, the Planorbis, the Physa, 

 the Vivipara and some of the "pigmies" 

 just mentioned. Much can be learned 

 concerning the habits of our common 

 snails if a record is kept of everything the 

 animal does, such as its mode of eating, 

 what it will eat and the increase in size 

 from day to day of the little snails after 

 they are hatched from the egg. If these 

 creatures could be considered by the ma- 

 jority of people as living, breathing ani- 

 mals, performing many of the functions 

 carried on by our own bodies they would 

 be regarded with mone favor and hence 

 aquaria would become more numerous 

 and they would also be studied more in- 

 telligently. The writer has been frequent- 

 ly amused (and sometimes pained) by the 

 careless question of some otherwise in- 

 telligent person, when he has been ex- 

 hibiting the shell of some interesting 

 mollusk, "Well, really, now, was that 

 thing ever alive?" It is to be earnestly 

 hoped that this series of articles will 

 reach many of this class of people and 

 lead them to a better understanding of 

 these lowly creatures. 



Frank Collins Baker. 



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