Rate of Growth in Dog. 



97 



66 (762) 



The rate of growth in the dog. 



By Sutherland Simpson. 



[From the Physiological Laboratory, Medical College, Cornell 

 University, Ithaca, N. Y.] 



Observations have been made on twenty-one litters. As soon 

 after birth as possible, when the amniotic fluid had been dried 

 off, each individual was weighed and at the same time it was ear- 

 marked and the sex determined. For the first three or four weeks 

 the weights were taken daily, at the same hour (4 to 5 p.m.), and 

 later every third day. From the figures obtained curves were 

 plotted showing graphically the absolute weight increments and 

 the rate of growth. The figures for the number of young, the 

 proportion of the sexes, the birth mortality, and the body weights 

 when born, are given in the following table. 



No. of 



Number Born. 



Average Weight at 

 Birth. 



Litter. 



Alive. 



Dead 



Total. 





<? 



9 





9 





& 



9 



I 

 2 



4 

 4 



4 



2 



I 





8 

 7 



294 

 278 



289 

 280 



3 





4 







4 





271 



4 



4 



4 







8 



270 



266 



5 

 6 



6 

 4 



5 

 4 



I 





12 

 8 



279 

 280 



274 

 268 



7 



3 



4 







7 



298 



294 



8 



1 



7 







8 



255 



286 



9 



1 



2 







3 



354 



288 



10 



4 









4 



309 





11 



2 



3 







5 



255 



245 



12 



3 



3 







6 



278 



297 



13 



3 



S 







8 



3io 



310 



14 



4 



4 







8 



269 



218 



15 



3 



2 



I 





6 



242 



253 



16 



1 







1 



2 



3i8 





17 



4 



6 





1 



11 



305 



294 



18 



1 



1 







2 



365 



297 



19 





3 







3 





299 



20 



5 



2 



I 





8 



344 



322 



21 



1 



4 



I 





6 



238 



241 





58 



69 



5 



2 



134 



292 



279 



The number of young in a litter varies from 2 to 12, families of 

 8 occurring most frequently. The proportion of the sexes is in 

 favor of the female, the ratio being 100 males to 119 females. 



