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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



were used at the rate of i gm. of salt to 25 cc. of water (table 2). 

 Pieces of cotton of equal size were wet with tap water and with the 

 three salty solutions, and then they were put on the pieces of card- 

 board, as already described. 



(2) Beetles can distinguish differences between water and sour 

 liquids. — To ascertain whether the above statement is true, three 



Table 5. — Tests to determine whether Mexican bean beetles can distinguish 

 differences between zvater and siveet substances 



sour liquids were used, each of two being prepared at the rate of ^ cc. 

 of glacial acetic acid (99.5 per cent) or hydrochloric acid (85.9 per 

 cent) to 25 cc. of water, and the third at the rate of 4 cc. of lemon 

 juice to 21 cc. of water (table 3). 



(3) Beetles can distinguish differences between zvater and bitter 

 liquids. — To determine whether the above statement is correct, four 

 bitter liquids were used, each of three being prepared at the rate of 



