INDEX 
References are to pages 
A 
Age of trees, how told 
266 
Agencies of seed distribution . 
241 
Abdomen, of crayfish . 
60 
Aggregate fruit. 
of grasshopper . . . 
23 
Agriculture, amount and kind 
Abnormal growth of tissue 
of cultivation in . 
231 
cause of disease 
487 
education for. 
245 
Absorbing pads of dodder 
253 
as an industry. 
245 
Absorption, of food, defined 
5, 
413 
influence of on civilization . 
296 
of food not nourishment . 
415 
Air, home of bacteria .... 
310 
Absorption in leaves 
of 
Air cells of lung. 
444 
Venus’s fly trap . 
367 
Air chamber of marchantia . 
331 
Accessory fruits . . . . 
237 
Akene . 
237 
Accessory parts of flower 
198 
Albumen, example of protein . 
416 
Acid medium in stomach 
411 
Alcohol, ambition destroyed by 
482 
Aconite, a poison . 
479 
a narcotic. 
479 
source of. 
297 
a poison. 
487 
Acquired immunity 
510 
and disease. 
506 
Action of voluntary muscle . 
438 
and patent medicines . ’ . . 
506 
Active bacteria reduced 
in 
cause of disease. 
487 
number by heating milk 
314 
chemical composition of . 
415 
Adam’s apple . 
445 
effect of, on circulation 
456 
Adaptation, discussed . . . 
1-4 
on digestion. 
430 
Adaptations, of honeybee 
49 
on nervous system . . . . 
480 
of fleshy fruits .... 
239 
formed by yeast plant . 
321 
of fruits for distribution 
in bread driven off by heat . 
427 
by animals. 
241 
not a food. 
416 
of fruits to distribution 
by 
/ 
Protozoa and. 
150 
water. 
241 
shortens life. 
478 
of a leaf . 
287 
use of in consumption . . . 
492 
of reptiles . . . . . 
104 
Alcoholism a disease .... 
482 
of the seed. 
219 
Ale, use of yeast in making . 
321 
of wood. 
263 
Alfalfa, member of pulse family 
299 
Adenoids . 
449 
root system of. 
252 
Adductor muscles of clam 
186 
Algae, class of Thallophytes . . 
9 
Adulteration, of cereals . . 
428 
lack of conducting system 
of foods. 
428 
in. 
370 
of milk. 
428 
Alimentary canal, of frog . . 
86 
Adventitious roots .... 
252 
of man. 
404 
experiments to show . . 
379 
Alkaline medium in mouth . . 
411 
Aerial roots . 
251, 
252 
Alligators, classified .... 
9 
Afferent fibers . 
470 
described. 
104 
Agar-agar, formula . . . 
312 
example of reptiles .... 
99 
1 
