ECONOMIC RELATIONS OF OUR BIRDS. 
513 
Tabular Summary of Economic Relations shoiving the number of specimens con¬ 
taining animal and vegetable food, and the number of insects, spiders and 
7nollusks taken from the stomachs, classified as to economic relations under 
the heads Benejicial, Detrimental and Unknown Relations. 
Number and Name op Speci¬ 
mens Examined. 
Classification 
OP Food. 
Ratios Represented by Lines. 
11 
Animal food. 
Of eleven Bam Swal- 
Vegetal food. 
1 
3 
1 
Beneficial. 
i 
4 
a 
o 
35 
Detrimental . . 
5 
O 
28 
.. . ^ 
14 
Animal food. 
tS 
Vegetal food. 
Of fourteen White-bel- 
6 
0) 
.a 
33 
lied Swallows exam¬ 
ined . 
9 
7 
68 
62 
O 
a 
1 
Animal food. 
■ 
One Eave Swallow ex¬ 
amined . 
'd 
d 
Vegetal food. 
1 
3 
2 
Beneficial. 
■ 
1 
19 
Detrimental. 
o 
1 
6 
Unknown. 
5 
Animal food. 
Of five Purple Martins 
O) 
P 
Vegetal food. 
5 
"S 
28 
Beneficial. 
■P—inMuw 1 jwLJimyi^jiijji 
2 
p 
O 
a 
2 
Detrimental. 
f 
12 
Unknown. 
3 
Table showing the iiumber and kinds of insects, spiders and mollusks eaten by the 
Stvallows. 
Number and Name of Speci¬ 
mens Examined. 
Classification 
OF Food. 
Ratios Represented 
BY Lines. 
Of fourteen White- 
bellied Swallows ex¬ 
amined . 
5 
3 
13 
3 
2 
G 
1 
14 
(U 
.a 
cl 
5 
10 
63 
23 
2 
33‘ 
1 
142 
Hymenoptera.... 
Diptera. 
Beetles . 
Hemiptera . 
Grasshoppers .... 
Dragon-flies . 
Spider . 
Adult forms . — 
VoL. 1—33 
