ON COLLECTING SHELLS. 281 



a solution of chloride of calciutn — a hygroinetric salt that always 

 retains enough moisture to remain in solution under ordinary 

 conditions of atmosphere and temperature. 



Physa, Limnsea and Planorbis must be scalded and the 

 animals removed with the land-shell hooks, and they should 

 afterwards be treated in the same wa}'. If stained treat them 

 with oxalic acid, using it judiciously, and you can clean the 

 worst of them perfectly'. Amnicola, Bythinella, Gillia, Soma- 

 tog3'rus, etc., small univalves almost universally stained, should 

 be put into the test tube with the sand and a small amount of 

 the oxalic solution, and shaken as before described for the small 

 land shells. They can thus be rendered perfectly clean and all 

 stains will be removed. You should not undertake to remove 

 the animals from these small shells, as if collected in alcohol as 

 before described, the animals will be much shrunken, and when 

 dried will not disfigure the shell particularly. Sometimes, as in 

 Physa hypnorum^ the soft parts adhere rather persistently within 

 the apical whorls. In such cases, after the shells have been 

 scalded, take up each specimen singl^r with the pliers and hold 

 the apex a few seconds against the blaze of a lamp or candle. 

 Soon a small quantity of steam forms with a slight explosion 

 that loosens the soft parts perfectly ; a jet of water from the 

 syringe will then remove the soft parts and rinse the shell at one 

 operation. 



Pisidium and all the smaller Sphserium are often stained, and 

 should be put in the test tube and treated in precisely the same 

 way. The larger species may be scalded, and the animal removed 

 as above described for the Uniones. 



In conclusion, I wish to impress upon all collectors the advan- 

 tage of having good, clean, perfect specimens of whatever 

 objects of natural history they undertake to study. If the 

 characters are obscured by dirt, or obliterated by decay or 

 erosion, 3^ou have no right to complain if those of better tastes 

 in these matters, and of more industry, reject as worthless these 

 evidences of your want of either one or both of these requisites ; 

 but if you faithfully follow the suggestions here made, there will 

 be no complaint that you lack either. 



The above remarks are intended to facilitate the work of 

 collectors legitimately employed in the advancement of science. 

 Wanton destruction of life will always be deprecated by the 

 naturalist as b}^ the moralist. Do not collect for the fun of 

 collecting ; have a purpose, and when that purpose is fulfilled, 

 stop. Take nothing unnecessarily — not even the life of a snail. 



In arranging a series of species in his cabinet the collector, if 

 unacquainted with their names, may group his species according 

 to those analogies and obvious resemblances that show their 

 relations to each other. He should attach a label to each species, 

 designating it by a numbfer xantil he has opportunity to replfece 



