TllK TO UP/C DO 



1 1 1 



lined i»v rest; it is also increased by energetic circula- 

 tion and respiration. As in muscular exertion the elei 

 cal power is increased by the action of Btrychnine. 



Ma ivy baa more recently made int< 

 on the torpedo, examining the discharge of this 6sh with 

 the telephone Slight excitations provoked a short croak- 

 30und. Each of the small discharges was compost d >•: 

 ;i dozen fluxes and pulsations, lasting about one fifteenth 

 of a second. The sound gut from a prolonged discha _ . 

 however, continued three to four seconds, and consisted of 



Fio. 101.— The Devil-fish. (O ratoptt ro). From Ldtken'a Zoology. 



a sort of groan, with tonality of about mi (165 vibrations), 

 agreeing pretty closely with the res t graphic ex] 



incuts. 



Marey has also studied the resemblai : the electrical 

 apparatus of the electrical ray or torpedo and a mus 

 Both are Bubject to will, provided with nervesof centrif 

 action, have a very similar chemical composition, and 

 semble each other in some points of structure. A mi 

 in contraction and in tetanu ites a number of sui 



sive small movements or Bhocks, and a like complexity has 

 been proved by M. Marey in the disch . _ 



The sting-rays {Trygon) have no caudal tin. but the 

 spinal column is greatly elongated, very slender, and armed 



