ANIMAL MECHANICS. 



1«3 



touching AB at the point Z, and let fall the perpendicular 

 0 U - p, from the vertex upon the base of the triangle. 

 It is easy to see that 



OAZ = fi-0 

 OBZ =p+Q 

 cot |(g - 01 = AZ 

 cot 4Q3 + 0) ~ BZ 

 OU = p = b sin/3. 



Therefore 



The work inherent in a triangular muscle is proportional 

 to the perpendicular let fall from the vertex upon the base, 

 multiplied by the Napierian Logarithm of the ratio of the seg- 

 ments of the base made by the point of contact of the exscribed 

 circle ; 

 and 



The work done by the same muscle will be proportional to 

 double the perpendicular let fall upon the side of the triangle 

 from the foot of the bisector of the vertical angle. 



In the case of the biceps femoris of the Lion, I made the 

 following measurements : — 



P = 3- 28 



AZ= 9.56 



BZ = 2.72 



q = 1.85. 



From these data we find — 



P lOga 3-28 x I.25 - 4-10, 



and 



2q = 3.60. 



