18 
INDEX 
References are to pages 
Hay infusion for protozoa 
143 
Hinge ligament of clam . 
186 
Head, cluster of flowers . . . 
214 
Hinge of clam .... 
186 
of grasshopper. 
22 
Hinge teeth of clam 
187 
Headache medicines .... 
507 
Hip bones of man . 
434 
Head end of earthworm . 
179 
Hogs, inspection of 
177, 500 
Heads, inflorescence of com- 
Hollow bones of birds 
109 
posite family. 
206 
Hollow stem, of horsetail 
338 
of a bone. 
436 
of parsley family 
300 
Head-thorax region of crayfish 
60 
Holly, use of wood of . 
352 
Health. 
487 
Hollyhock, member of mallow 
laws. 
464 
family. 
299 
Healthy bodies and bacteria 
316 
Home making, work of women 
426 
Hearing. 
475 
Home study of moths 
and 
Heart, of man. 
451 
butterflies .... 
44 
center. 
481 
Honey, amount of carbohydrate 
muscle cells. 
437 
in. 
410 
of crayfish . . . . 
64 
value of, in U. S. . . 
49 
valves of. 
452 
Honey-bee, discussed . 
45 
Heart and blood-vessels of 
development .... 
46 
man. 452, 453 i 
worker, queen, drone . 
46 
Heartwood. 
353 
Honey-bees clustering 
at 
Heat and pressure, influence 
swarming^ time , . 
48 
of, in forming coal . . . 
339 
Hoofs of cattle, origin of . 
459 
Heating, common methods of 
447 
Hooks, on fruit of burdock 
241 
milk, effect on bacteria . . 
314 
on fruits, use of . . : 
241 
protection of bacteria from . 
311 
Hookworm disease . . 
494 
Heel of man. 
434 
Hop lice destroyed by lady-bugs 
34 
Heliotropism, defined .... 
286 
Horehound, a medicine . 
300 
Hellebore, source of ... 
297 
Horned toad, a lizard . 
101 
Helpful bacteria. 
311 
Horns of cattle, origin of 
459 
Hemiptera, discussed .... 
58 
Horse, classified 
9 
order of insects. 
29 
discussed. 
129 
Hemlock, bark, use of 
346 
evolution of ... 
126 
conifer.. 
345 
use of. 
126 
Herbaceous plants. 
261 
Horse-chestnut, as shade tree . 
364 
Heredity, discussed . . .96, 532 
compound leaves of 
277 
of disease. 
516 
Horse-radish, member of mus- 
Hermit crabs, economic impor¬ 
tard family.... 
298 
tance of. 
65 
Horsetail. 
337 
Herons, beak of. 
109 
joints of stem 
338 
Herring, economic importance 
Horsetails, members of 
fern 
of. 
71 
group. 
333 
Hibernation, defined .... 
84 
related to ferns . 
333 
study of. 
140 
scouring rush .... 
Hickories, members of walnut 
Host, defined .... 
41 
family. 
of liver fluke .... 
176 
source of nuts. 
351 
Hotels, examination of hell 
> for, 
501 
wood, uses of. 
352 
House-fly. 
. 54. 57 
Hills, a method of planting . 
376 
killed by fungus . 
323 
Hilum of bean. 
219 
House-sparrow, scientific name 
Hinge joint. 
435 
for. 
10 
