244 EMBRYO PENGUINS OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 



Fig. 23. Gentoo penguin embryo of 24 days. Notice the character of the fore limb, and the attitude of 

 the hind limb and tail. 



Fig. 24. Gentoo penguin embryo of 25 days. 



Fig. 25. Gentoo penguin embryo of 27 days, to show the stage of development reached before leaving 

 the shell. 



Fig. 26. Photograph of fore limbs of gentoo penguin embryo of 22 days, to show ossification. 



The clear portions of the shafts are composed of bone, and the dark extremities are of cartilage. Both 

 extremities of the radius and ulna are cartilaginous. Beyond them is a darkish area, in which are the 

 cartilaginous rudiments of the carpus. 



Beyond that region are the metacarpal bones and phalanges. 



