Tenth c.c. 

 per liter 



CHART II. 



Death Curve of Lepomis Humilis in Ether. 

 ((C 2 H 6 ) 2 0.) 



CHART II. (Ether death curve.) The curve to the left is the "abnormal 

 curve" and marks the inception of symptoms such as loss of balance. The obvious 

 fall in toxicity below 420 cu. mm. per liter is shown by the stippled death curve 

 turning off to the right. Class i was of fish 2-9 grams in weight; class 2 was of 

 fish 10-19 grams in weight; class 3 of fish 20-25 grams in weight. The significance 

 and curve directions are discussed in the text. It is very likely there would have 

 been much intercrossing if many experiments had been run and ten or more classes 

 had been separated. It may be that difference of physiological condition of different 

 batches of fish (as chance allots in the purchase of fish for standardizing) may give 

 results with the same concentration of the same drug as far apart as the different 

 weights of fish here have done. In the case of the fish used here all were caught 

 in the same place, and kept in constant environment in the same tank until used. 



The upper and lower boundaries of the curve at the lower right hand edge of 

 the cart were determined by experiments not shown in the graph. I am indebted 

 to Miss Dorothy Wing, of the University of Chicago, for aid in the preparation of 

 this chart. 



