INDEX 13 
References are to pages 
Enzymes. 
14, 412 
Exercise, benefits of . . 
447 
of yeast plant . . . 
. 321 
necessary to keep one fit 
440 
secreted by bacteria 
. 311 
value of. 
440 
Ephemeridae, an order of 
in- 
Exercising, out-of-doors . 
447 
sects . 
29 
to keep well .... 
447 
Epidemic, defined . 
. 515 
Exhalent pores .... 
156 
Epidemics, after wars . . 
. 514 
Exhalent siphon of clam . 
185 
of diseases, costliness of 
. 514 
Exoskeleton, of crayfish . 
60 
sore throat . . . 
. 499 
of grasshopper . . . 
25 
Epidermal tissue of pteris stem 334 
Experiment, to show production 
Epidermis, of root . . . 
. 247 
of carbonic acid in plants 
280 
of leaf .... 
performed on plants . . 
229,280 
of rootlets. 
. 248 
stations. 
377 
of xerophytes, character 
of 371 
Expiration, defined. . . . 
445 
outer layer of skin . . 
. 459 
Explosion of fruit case 
to 
Epiglottis. 
. 444 
scatter seeds . . . . 
237 
r , 238 
Epiphytes, definition of . 
253, 373 
Extent, of original forest. 
348 
habitat of. 
. 373 
of root system .... 
252 
Epsom salts in cosmetics 
. 504 
External appearance of woody 
Equisetum. 
. 338 
stems 
264 
Erosion checked by roots 
. 256 
External parts of fish . 
71 
Eskimo, diet of ... 
15 
Extinct animals, remains of . 
95 
surroundings of . 
97 
Eye . 
472 
Esophagus, of crayfish 
. 63 
Eyeball. 
472 
of earthworm .... 
. 181 
Eyelid. 
472 
of frog. 
. 85 
Eyes, of fish. 
75 
of man. 
. 408 
of grasshopper .... 
22 
Essential parts of flower . 
199,201 
of man. 
472 
Ether, an anesthetic . 
. 480 
of man, care of ... 
475 
test for oil. 
. 228 
of Nereis. 
184 
Eustachian tube, of frog . 
. 83 
of vertebrates .... 
70 
of man. 
. 406 
Evaporation of perspiration 
ef- 
F 
feet of .... . 
. 459 
Evening grosbeak, winter vis- 
Faeces, removal of . 
415 
itant .... 
. 112 
Fainting, cause of ... 
456 
Evergreen, leaves defined 
. 341 
False blossoms. 
243 
trees, examples of . 
. 345 
Fangs of rattlesnake . . . 
101 
Evergreens, characteristics o 
. 341 
Farmers’ Bulletins .... 
526 
Examples of plant societies 
. 370 
Fascicled roots. 
251 
Excelsior, source of 
. 352 
Fatigue of muscles 
439 
Excretion, a life process . 
5 
Fats, a class of foods . 
410 
definition of ... 
5 
absorption of. 
414 
in crayfish. 
. 63 
furnished by animals . 
416 
in grasshopper 
. 25 
nutrients. 
13 
in plants. 
. 282 
Fear of snakes. 
102 
of hydra. 
. 163 
Feathers, a characteristic i 
of 
of man. 
. 443 
birds. 
110 
of mollusks .... 
. 188 
of birds, modifications < 
of 
Excurrent stem of ever- 
skin. 
459 
greens. 
265, 341 
Federal Plant Quarantine Act 
522 
