218 THE VOYAGE OF H.M.S. CHALLENGER. 



Table showing the size of the Renal Organs in various species of Penguin in inches. 



GENERATIVE ORGANS. 



Male Organs. 



T/ie Testicles (PI. XVII. fig. 7) in every species of Penguin are arranged as in other birds. 

 Each is situated on the under surface and close to the anterior border of the corresponding 

 kidney. In Exidijptes chrysocome each measures ^ an inch in length and \ of an inch in 

 breadth. The testicle is of a dark purple colour, elongated oval in form, and somewhat 

 laterally compressed. The vas deferens comes ofi" from the posterior border of the testicle 

 and passes horizontally backwards, lying at first in contact with the lower surface of the 

 kidney, and afterwards with the superior abdominal wall. As it passes backwards, the 

 vas deferens lies along the outer side of the corresponding ureter, and terminates by 

 opening upon the upper wall of the posterior compartment of the cloaca. The cloacal 

 orifice of each vas is situated on the extremity of a nipple-shaped projection of somewhat 

 smaller size and situated to the inner side of that on which the ureter opens.. 



Variations. — The male generative organs do not present any variations from the 

 arrangement above described in Euchjptes chrysocome. It may be of interest to state 

 that in nearly every specimen examined the testicle of the left side was considerably 

 larger than that of the right, which suggests the question whether there may not be a 

 tendency on the part of the male gland of the right aide to undergo a process of atrophy 

 similar in character to that Undergone by the homologous female gland of the same side. 



