30S 



HENRY H. DONALDSON 



APPENDIX 1 



SKELETON— ALBINO RAT 



The accompanying table 31 gives the parts of the skeleton fol- 

 lowed by the number, or groups, of bones separately weighed in 



TABLE 31 

 Parts of skeleton 



DIVISION 



Skull 



Axial skeleton < 



Appendicular 

 skeleton 



Shoulder 

 girdle and 

 appendages 



Pelvic girdle 

 and appen- 

 dages 



NAME 



Cranium (with 6 ear bones 



and 8 teeth) 



Mandibles (with 8 teeth).. 



Hyoid 



Vertebrae of trunk 1 

 Vertebrae of tail J 

 Ribs 1 

 Sternum] 



NUMBER 



OP 

 WEIGH- 

 INGS (2 = 

 BIGHT AND 



LEFT 

 WEIGHED 

 SEPARATE- 

 LY) 



Scapula 



Clavicle 



Humerus 



Ulna 



Radius 



Carpus and bones of fore- 

 feet 



Pelvis 



Femur 



2 sesamoid bones behind 



distal end of femur 



Patellae 



Tibia and fibula 



Tarsus and bones of hind 



feet 



Totals 



1 

 1 

 1 



1 

 1 



2 

 2 

 2 



2 

 2 



1 



2 



2 

 2 



2 



28 



TOTAL 

 NUMBER 



OF 

 SEPARATE 



BONES 



PREPARED 



IN EACH 



GROUP 



1 



2 



1 

 / 30 



30* 



26 

 \ 6 



2 



2 

 2 

 2 

 2 



56 5 



2 

 2 



4 

 2 



4 6 



54 5 



230 



4 The number of caudal vertebrae is somewhat variable (twenty-eight to 

 thirty), but in the mature rat there are about thirty. On the ventral aspect 

 of the caudal vertebrae — in the intercentral position — are a series of pairs of 



