The Intra-Uterine Growth-Cycles of the Guinea-Pig. 



711 



Table I. 

 Actual, observed weights. 



into another, a distance of 50 feet perhaps. The disturbance was 

 sufficient to cause one of the animals to give birth prematurely 

 (59 days) to a litter of three. 



The low weight at copulation in the four cases under conside- 

 ration I belive to be due to the excitement and muscular work which 

 is always attendant when a male is put into the pen with a female. 

 The chasing is often quite severe and continues for some time. Upon 

 many occasions I have noted a loss of weight after copulation. 



