INDEX 
5 
References 
Blue jay, feeds on larvae of 
Lepidoptera.42 
Blue racer, a constrictor . . 102 
Boa-constrictor. 102 
Boards of Health.507 
Bobolink, food of. 117 
migratory habits Qf . . 111,112 
nesting habits of . . . . 112 
Body, parts of in fish ... 71 
Body cavity of earthworm . . 180 
Body temperature of birds . . 110 
of mammals.125 
of man. 459 
Bone ache.492 
Bone, cells of. 433 
structure of.436 
Bones, broken. 435 
Boneset, medicinal plant . . 292 
Bony fishes, examples of. . 71 
Borax, a preservative . . . 314 
in cosmetics.504 
Borers, harmful beetles ... 34 
eaten by downy woodpecker 114 
Boric acid, a preservative . . 314 
Botfly, harmful insect.... 54 
Bottling, good and bad . . . 315 
Boxwood, use of.352 
Bracken fern. 333 
Bracket fungi, effect on trees . 324 
Brain, efficiency, discussion of . 476 
efficiency, conditions neces¬ 
sary for.476 
“ Brain ” of earthworm . . . 181 
Braincase of frog. 88 
Bran, used as an adulterant . 428 
Branch, example of organ . . 7 
of pine, position of ... . 342 
Brazil nut, a seed.245 
Bread, crumbs for feeding sta¬ 
tion .117 
making.426 
mold.323 
mold, laboratory study of . 325 
use of yeast in making . 426, 427 
Bread-making, scientific basis 
of.321 
temporary by-products of 321, 427 
Breast bone of birds .... 109 
Breathing center in developing 
embryo.481 
in grasshopper. 21 | 
to pages 
Breathing — continued 
in man . . 445 
not respiration. 5 
Brewing, scientific basis of . . 321 
Bromide of potassium . . . 503 
Bronchitis. 449 
Bronchus. 444 
Brook trout raised in hatcheries 78 
Brown creeper, at suet station 118 
food of.42, 114 
Brown hydra.160 
Brown rat. 135 
Browntail moths. 525 
Brussels sprouts, flowers of . . 217 
Bryophytes classified .... 9 
Bubbles of oxygen in masses of 
spirogyra. 306 
Bubonic plague, a bacterial 
disease. 489 
Bud, in reproduction of yeast 
plant. 322 
Budding cells of yeast 322 
Buds, a characteristic of stems 264 
Bugs, members of Hemiptera . 29 
Bullfrog, time required for 
development. 93 
Bullhead, organs of smell in 76 
Bumble bee, carrier of pollen . 45 
economic value of ... 45 
Burbot, a bony fish .... 79 
Burdock, common weed . . . 301 
distribution of seed by ani¬ 
mals .241 
Bureau of Chemistry . . 505, 526 
Bureau of Entomology . . . 525 
Bureau of Fisheries .... 526 
Bureau of Plant Industry . . 526 
Butcher bird (shrike) . . . . 112 
Butter, example of fat ... 416 
flavor of, due to bacteria . . 311 
indirect product of plants . 376 
value of as food.416 
Buttercup, characteristic mem¬ 
ber of crowfoot family . . 297 
Butterflies, classified ... 9, 29 
complete metamorphosis of . 28 
Butterfly, swallowtail, from cel¬ 
ery worm. 41 
larvae of. 41 
Buzzards, food of.116 
By-product of photosynthesis . 279 
