XIII.] THE FKOG. 217 



the other on the astragalar side, articulate. 

 The latter is connected by ligamentous fibres, 

 within which a nodule of cartilage may be 

 found, with the first and second metatarsals, 

 and supports the calcar (d. f). 



d. The digits. Five in number; the internal one 

 the shortest, the fourth the longest. Their com- 

 position 



a. The first, or hallux (the most internal) ; a 

 metatarsal bone, followed by two phalanges. 



/3. The second : same as a, but longer. 



7. The third : a metatarsal bone with three pha- 

 langes. 



S. The fourth: a nretatarsal bone and four 

 phalanges. 



e. The fifth : like the third, but a little shorter. 



f On the anterior or tibial edge of the foot there 

 are two, small, more or less cartilaginous, ossicles, 

 articulated with the tarsus (c. /3) in such a 

 manner as to resemble an extra digit. This 

 ealcar, or spur, supports the horny prominence 

 referred to above. 



E. DISSECTION OF THE FROG'S HIND-LIMB TO ILLUSTRATE 



ITS MYOLOGY, 



(For the following dissection it is desirable to have a frog 

 which has been lying some time in spirit.) 



1. Lay the animal on its back, and make an incision 

 through the skin on the front of the limb from the 

 symphysis pubis to the ankle; then reflect the skin 



