220 Mr. Home on the Mode of breeding 
Explanation of the Plates. 
Plate IX. 
An internal view of the belly of the oviviviparous dog-fish, 
squalus acanthias, of Linnjeus: to show the organs of gene- 
ration in their natural situation, when in a state fit for 
impregnating the female. 
a The heart. 
b b The liver. — The left lobe is cut away to expose the 
parts behind. 
c The ^esophagus. 
d The cardiac portion of the stomach. 
e The pyloric portion. 
f The small cavity between the pylorus and duodenum. 
g The duodenum. 
h h The valvular intestine. 
i i An appendix to the intestine with which it communicates. 
k k The testicle. 
1 1 The vas deferens, the lower portion of which is straight, 
and distended with semen. 
m The cavity which is the reservoir of semen, and urinary 
bladder. 
n The kidney. 
o The penis. 
p p Tw'o external openings leading into the cavity of the 
abdomen. 
q q The two holders in their collapsed state. 
Plate X. 
The holders in their extended state, as they appear when 
the male is clasping the female. In this state of the parts, the 
