METHODS OF KEEPING RECORDS 523 



Fig. 71. Code for marking ears. 



t 



Examples 



27 _ -. a 85 40 04 



6 K 50^ ^J05 Sjde Vjew 



* — ' — ^ fin 06 



60 06 



'9 70 07 



C^\ 



90 09 



80S h 08 



The animal is viewed from the back. Tens are on the left ear and digits on the right 

 ear. Code marks at the top and bottom of the ear should be punched as close as possible 

 to the head. Code marks on the side of the ear should be punched close to the end of the 

 ear fold (see side view). If these precautions are observed, there will be little confusion 

 about the code number. Many times the punch pulls out the edge of the ear, but the distinc- 

 tion remains recognizable because the notches are very shallow in comparison to the pulled 

 holes. 



used, the information in the ledger includes the following biographical information. 



1 . Number of the mouse being pedigreed 



2. Sex of the mouse being pedigreed 



3. Phenotype, if needed 



4. Fate of the animal (whether it was put in a new mating pen, set aside for a 

 particular experiment, or classified and killed) 



5. Parents of the animal 



6. Generation to which it belongs 



7. Date of birth 



A line is drawn across the page after all animals from one litter are pedigreed. The 

 next line is the beginning of a new litter (figure 72). 



In mutant stocks and various other types of experimental animals, it is necessary 

 to record the phenotype of the animal. The logical location of this information is 

 after the sex of the animal, as previously noted. When such notations are made, the 

 symbol + is standard for the wild type or normal allele, especially in classification of 

 mutant stocks (figure 73). 



Some systems of keeping records employ a single ledger or two ledgers for each 

 stock and assign each mating a double-page space for all information concerning off- 

 spring of that mating. 



