NEUTRON EFFECTS OX ANIMALS 



119 



illustrated by the growth cur^•e in Fig. 2a for rabbit Xo. 10 given 55 n at 

 two widelj' separated times. With a greater number of 55 n doses, some 

 animals showed an immediate cessation of growth or loss of weight while 

 others exhibited a continued growth, though only temporarily, in spite of 

 irradiation. The latter effect is illustrated by the growth cm-ve in Fig. 2b 

 for rabbit Xo. 25. 



W 



10 ZO 30 40 SO 60 TO SO 90 100 



m 



J.0 ZO JO 40 SO 60 TO 80 90 XOO 



[c] 



no 



IZO 

 1X0 

 100 



/On/ DAY 



UlUMlliMUUlJ UM or^ 



15 ABB IT NO Z9 



1,1, 



I I ! 







10 10 30 40 SO 60 TO 80 90 100 



Fig. 2. Relationship between neutron irradiation of rabbits and their body weights. 

 The ordinate represents weight in ounces; the abscissa, time in days. Arrows indi- 

 cate days on which the irradiation was administered. 



Irradiation with 10 n/day usually caused a decrease in gi'owth rate fol- 

 lowed by an actual decline in weight, as shown for rabbit No. 29 in Fig. 2c. 



Physical Abnormalities Resulting from Irradiation. During the experi- 

 ments, certain physical changes in the animals were so outstanding that 

 they could not escape notice. One was alopecia, which first appeared 

 about the nose and eyes, and finally spread over the entire bodies of the 



