528 



APPENDIX 



Fig. 74D and E. Mating card and litter card. 



BATING CARD 



LITT1H CAHO 71 M ILO 



For certain types of experiments, a system has been devised which omits the use of the 

 ledger. The system uses a mating card (D) and a litter card (E). Across the top appears 

 the cage number (a) , the strain (b) , the generation (c) , the parents of the pair being made up (d) , 

 the numbers of the pair te) , the dates of their birth (/) , and their genotypes <9> . The columns 

 are for date of mating (,l) , date of pregnancy (i) , date of birth of litter (;) , number born minus 

 number dead (fc) , the number weaned (0 , the number killed (m) , the number raised (n> , card 

 number of litter (0) , and remarks (p) . 



Card numbers for litters are stamped in serial order, and this number appears at the 

 left of the number 1 on the litter card (E). The top of the litter card carries the same 

 information found on the mating card, omitting only the numbers of the grandparents. 

 The individuals in the litter are marked according to the numbers 1-0, sex recorded in 

 the next column, then phenotype, genotype, fate of the animals, and date when their fate 

 was determined. The last column provides space for remarks about each individual. 



