THE EEL. 345 



is very low. Dr. Marshall Hall has shown that the quantity of respi- 

 ration is inversely as the degree of irritability. With a high degree of 

 irritability and low respiration co-exist : 1st, the power of enduring the 

 deprivation of air and food ; 2nd, a low animal temperature ; 3rd, little 

 activity ; 4th, great tenacity of life. All these peculiarities eels are 

 well known to possess. The high degree of irritability of the muscular 

 fibre explains the restless motion of eels during thunderstorms, and helps 

 to account for the enormous captures made in some rivers by the use of 

 gratings, boxes, and eel-pots or baskets, which imprison all that enter. 

 The power of enduring the effects of a low temperature is shown by the 

 fact that eels exposed on the ground till frozen, then buried in snow, 

 and at the end of four days put into water, and so thawed slowly, have 

 discovered gradually signs of life, and soon perfectly recovered. 



Though this is undeniably true and reliable, the experiments of John 

 Hunter have placed the history of eels in this respect in a still more 

 satisfactory light. With a properly constructed thermometer he found 

 that the temperature of the stomach of a particular eel was 37 deg. He 

 then placed the eel in a mixture, which he first ascertained to be at 10 deg., 

 and this brought the temperature of the stomach down to 31 deg. ; the 

 creature appeared to be dead, yet on the following day it was restored to 

 full life and activity. 



This accomplished physiologist further noticed that the presence of 

 life allowed the vital heat to be lowered to two or three degrees below 

 freezing point, and after this it resisted all further decrease, and when 

 the power of life had become expanded by the exertion of thus resisting 

 decrease the creature became frozen like any other dead matter. 



It further appears by experiment that an eel, like the frog, can digest its 

 food when the heat is 60 deg., and loses this power when it is below 40 deg. 



This brings us to the food of the eel, which is an extensive subject. 

 Albertus Magnus stated that its food was entirely vegetable, but in the last 

 session of the Rhenish and Westphalian Natural History Society, O. 

 Melsheimer, reporting the results of experiments on eels through a long 

 series of years, entirely refutes this, and, on the contrary, proves the 

 food to be exclusively animal. He also mentions that it seems to be 

 extremely fond of the river lamprey (Petromyzon fluviatilis). My own 

 observation coincides with this. Out of many hundreds of eels whose 

 stomachs I have examined, I have never found vegetable matter except in 

 such positions as to clearly indicate its having been taken inadvertently 

 and involuntarily such, for instance, as when the contents of the 

 stomach of a smaller fish swallowed as food has been laid bare and 

 its vegetable nature revealed by the processes of digestion. 



Couch, however, says eels have been seen to devour the leaves of 



