Nov. 29, 1915 
Occurrence of Tumors in Domestic Fowl 
399 
data on all the birds, whether or not their exact ages were known, into 
two classes, young (under 2% years) and old (over 2% years). 
Table) II. —Relation of age and sex to the occurrence of tumors in the domestic fowl 
Age in years (mid¬ 
points of class). 
Females. 
Males. 
Males and females. 
Num¬ 
ber 
with 
tu¬ 
mors. 
Num¬ 
ber 
with¬ 
out 
tu¬ 
mors. 
Total 
num¬ 
ber. 
Per¬ 
cent¬ 
age 
with 
tu¬ 
mors. 
Num¬ 
ber 
with 
tu¬ 
mors. 
Num¬ 
ber 
with¬ 
out 
tu¬ 
mors. 
Total 
num¬ 
ber. 
Per¬ 
cent¬ 
age 
with 
tu¬ 
mors. 
Num¬ 
ber 
with 
tu¬ 
mors. 
Num¬ 
ber 
with¬ 
out 
tu¬ 
mors. 
Total 
num¬ 
ber. 
Per¬ 
cent¬ 
age 
with 
tu¬ 
mors. 
l A . 
5 
81 
86 
5.81 
0 
4 
4 
0 
5 
85 
90 
5 - 5 <S 
39 
424 
463 
8.42 
1 
24 
25 
4.00 
40 
448 
488 
8. 20 
. 
5 
105 
no 
4 - SS 
1 
3 
4 
25.00 
6 
108 
114 
5-26 
4 
60 
64 
6. 25 
0 
1 
1 
0 
4 
61 
65 
6.15 
Total, % to 2% 
years. 
S 3 
670 
72 3 
7-33 
2 
32 
34 
5-88 
SS 
702 
757 
7.27 
2^ . 
0 
0 
0 
3 
22 
25 
12. 00 
S 
18 
23 
21.74 
0 
1 
1 
0 
5 
19 
24 
20.83 
3^ . 
1 
1 
2 
50. 00 
0 
0 
0 
1 
i 
2 
50.00 
0 
z 
1 
0 
0 
1 
I 
0 
0 
2 
2 
0 
1 
0 
1 
loo. 00 
0 
0 
0 
1 
0 
1 
100.00 
0 
2 
0 
0 
0 
0 
0 
2 
2 
0 
5^. 
0 
0 
0 
0 
1 
1 
0 
0 
1 
1 
0 
6.. 
X 
0 
1 
100.00 
0 
1 
1 
0 
1 
1 
2 
50.00 
Total, 2^ to 6 % 
years. 
11 
44 
SS 
20.00 
0 
4 
4 
0 
11 
48 
59 
18.64 
Total, H to 6 f4 
years. 
64 
714 
778 
8.23 
2 
36 
_ 3 &_ 
5*26 
66 
750 
816 
8.09 
Exact age unknown: 
Young. 
1 
0 
I 
100. 00 
0 
2 
2 
0 
1 
2 
3 
33-33 
Old... 
11 
46 
57 
19.30 
i 
3 
4 
25.00 
12 
49 
61 
19. 67 
Total. 
76 
760 
836 
9.09 
3 
41 
44 
6.82 
79 
801 
880 
8. 98 
Table) III. —Summary of the data showing the relation of age and sex to the occurrence 
of tumors in the domestic fowl 
Age. 
Females. 
Males. 
Males and females. 
Total 
number. 
Percent¬ 
age with 
tumors. 
Total 
number. 
Percent¬ 
age with 
tumors. 
Total 
number. 
Percent¬ 
age with 
tumors. 
Young (% to 2% years). 
724 
7. 46 
38 
5 * 56 
760 
7*37 
Old (2% to 6 }i years). 
112 
19. 64 
8 
12. 50 
120 
19. 17 
Total. 
836 
9.09 
44 
6. 82 
880 
i 8.98 
This table shows that while only 7.46 per cent of the females under 
2 yf years have tumors, 19.64 per cent of those over q.% years are affected. 
The result for the males agrees essentially with that for the females, but 
the number of males is too small to allow us to consider this result as 
necessarily significant. It is, however, quite certain that the probability 
of the presence of a tumor in a bird increases as the bird grows older. 
The records available for this study show in which organs the tumor 
is located and whether it is of cystic or solid-tissue structure. These 
data are given in Table IV. 
