2IO 



CoUcijc of Forestry 



between marine and frcsli water fish as to their powers of 

 digestion is well stated by (iiinther ('80, p. 122) in the follow- 

 ing words : " On the whole, marine lishes are more voracious 

 than those inhabiting fresh waters; and whilst the latter may 

 survive total abstinence from food for weeks and months, 

 the marine species succumb to hunger within a few days." 



Table No. 54. Stomach Examinations of Gouy 



*A small amount of food in the intestiao. t3 specimens had a small 

 amount of food in the stomach, and empty intestine. 



Our fresh-water fish vary greatly in their food habits and a 

 considerable amount of investigation will be necessary before 

 enough data are availal)le upon which to base safe conclusions 

 as to their rate of digestion and on the amount of food eaten 

 by them. 



Professor T. L. Hankinson has given the matter some con- 

 sideration and the writer has consulted him freely. In the 

 course of my correspondence with him he wrote: "I have 

 no doubt that species and pr(jbably individuals vary greatly as 

 to the frequency of taking food, and the rate of digestion 

 would depend, as you know, on the kind of food and the 

 vitality of the lish. Some forms are almost never found with 

 empty digestive canals except at spawning time. This appears 

 to be a period of fasting for iish, judging from food studies 

 I have made, which are insuilicient for any definite conclusion 



