CONGDON: EFFECTS OF RADIUM ON LIVING SUBSTANCE.— II. 363 
Number of Strength of Hours on Duration of life Fate. 
experiment. radium. radium after radium. 
SMALL ADULT Worms. 
5 Weak rt 0 days Killed 
6 a9 5 ) “c a3 
7 iz 44 96 sé a4 
8 ‘ec 6 5 a9 “ce 
9 t 6 Dithy Noe Dead 
10 73 re @) (a3 ce 
11 i 6 BOw ie Killed 
1 ce 93 @) ing a4 
13 ce iby 4 ce a4 
14 3 ibs) rs es ea th 
15 . 15 op Dead 
16 (a3 15 48 ce 73 
CopuLATING WorMs. 
17 Weak 12 Q days Dead 
18 v 4 120 2s ;°" Killed 
19 Strong 3° pe Dead 
20 rad iy 48 120). 3" Killed 
» 1 a9 20 96 a9 a4 
29 a 26°" 9 eal Dead 
23 . 24 168 0% re 
24 % 24 2005 We Killed 
animals which were exposed. Most of the other fourteen gave signs 
of having suffered from the exposure before they were killed. Some 
became insensitive to tactile stimulus. Others showed alternate 
swellings and contractions along the body. One animal turned 
markedly browner than any of the others, although otherwise it looked 
normal. ‘There was some evidence of a darkening of other exposed 
animals, which was confirmed by a microscopic study of the body wall. 
The effort was made to fix the worms after degeneration was apparent 
in their tissues, but before death. That this was difficult to do, is 
indicated by the fact that half of the animals killed showed no internal 
injury, although they did show already some of the external indica- 
tions which have been mentioned. A comparison of the periods 
necessary to produce death of the animals of different ages, as repre- 
sented in the three subdivisions of the table, shows that the young 
animals succumb much more quickly than the adult. This may be 
due either to the greater sensitiveness of the tissues of the young, or 
to a simple physical condition, namely that, since the diameter of 
