XIII.] THE FROG. 203 



b. The white corpuscles, 



Less numerous than the red : their colour, size, 

 granular character, nucleus, and changes of form 

 (amoeboid movements) : see III. B, 



D. THE EXAMINATION OF A PREPARED SKELETON. 



The skeleton of a Frog may be prepared for ex- 

 amination by removing the viscera from the body, 

 and roughly dissecting away the muscles, &c. Then 

 place the remainder in water and let it macerate 

 for about a week; afterwards carefully pick away 

 the soft parts, with forceps, from the bones and carti- 

 lages. 



a. Its general arrangement, 



1. The central axis, consisting of the vertebral or spinal 

 column and of the central parts of the skull which 

 lie, in front of the spinal column, in the same antero- 

 posterior line. 



2, Lateral parts, supported, directly or indirectly, by 

 the axis. 



a. The appendages proper. (Limbs and limb-arches.) 

 a. The fore-limbs: their supporting shoulder- 



girdle or pectoral arch, not directly attached 

 to the axial column; the limb proper; its main 

 divisions; humerus, radius and ulna (the two 

 latter ankylosed), carpus and digits. 

 /& The hind-limbs: their supporting arch (pelvic 

 girdle), carried directly by bony processes pro- 

 ceeding from the vertebral column ; the limb 

 proper ; its main divisions, os femoris, tibia 

 and fibula (ankylosed), tarsus, digits. 



b. The facial and lateral cranial bones. 



