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PROCEEDINGS OF THE ACADEMY OF 



[July, 



opposite to that found by Danclino, yet it throws very Uttle light on the 

 bad effects caused by the presence of microscopic slides. 



As De Varigny used flat dishes in contrast to spherical flasks, his 

 cases of dwarfing by rearing in a small area can be referred with very 

 little doubt to lack of aeration. 



7. Volume. — Before the preceding series of experiments were com- 

 pleted, so before the bad effect of the presence of microscopic slides 

 was known in experiments with volume, the inside area of the two 

 similar jars was made equal by a structure of slides of calculated area. 

 The amount of water in the two jars was not the same, the smaller 

 volume of water containing the structure of slides. Experiments with- 

 out the structure were later tried, but all the experiments led to the 

 same result (Table XVII) : the snails in the smaller volume were the 

 smaller. 



Table XVH — Effect of Volume. 



Dandino, referred to above, found that in toxic solutions, i.e., weak 

 acids, the radicles of peas and corn grew longer in a small volume than 



