INDEX 
23 
References are to pages 
Menhaden, example of bony 
fish.71 
Mercury poison.487 
Meristem. 247, 267 
Mesentery of frog. 86 
Mesoglea of coelenterate . . 160 
Mesophyll of leaf.285 
Mesophytes, definition of . . 372 
Mesothorax of grasshopper . . 23 
Metal container dangerous for 
milk.316 
Metamorphosis ..26 
complete.27 
incomplete.26 
Metathorax of grasshopper . 23 
Metazoa, defined.152 
Method of pollination, basis of 
classification.210 
Methods, of breeding oats . . 389 
of attracting birds . . . . 117 
of control of house-fly ... 56 
Meyer, Hans, discovery of . . 480 
Mice, destroyed by hawks . . 115 
harmful mammals .... 135 
Microbes, a name for bacteria . 309 
Micropyle, of bean.219 
use of.220 
Microscope, inventor of . . . 316 
Middle ear.475 
Middle West, production of 
corn by. . 296 
Midrib of marchantia .... 331 
Migration of birds.113 
Milk, care of.316 
curd of, example of protein . 416 
from healthy cow, number of 
bacteria in.313 
indirect product of plants . 376 
Milk glands, characteristic of 
mammals.125 
Milt of fish.78 
Mineral matter in food ... 15 
Mineral substances .... 15 
Mink, harmful mammal . . . 137 
Mint family, characteristics of . 300 
Mints used for medicine and 
in food.-300 
Mistletoe, absorbing organs of 369 
a semi-parasite.369 
Mites, arachnids.65 
Mixed diet of man.411 
Model reservoir.463 
Modifications of plants . . . 366 
Modified cotyledon (scutellum) 
of corn.225 
Modified leaves of club moss . 338 
Moisture, a condition for 
growth of bacteria . . . 310 
for lichen gathered by fungus 325 
Molars of man.406 
Molds, classified. 9 
Moles destroyed by hawks . . 115 
Mollusca, classified .... 9 
number of. 9 
Mollusks, characteristics of . 185 
life history of.188 
shells of, home of hermit crab 65 
summary of.67 
Molting, of crayfish .... 61 
of grasshopper.25 
Monarch butterfly .... 39, 41 
Monkey, example of mammal . 9 
Monocotyledons, group of 
flowering plants .... 9 
represented by corn . . . 226 
seeds of. 227 
Monoecious flower, defined . 204 
of beech family.297 
of walnut family .... 297 
Morning glory, an annual plant 261 
a dicotyledon.227 
Mosquitoes, breeding places 54, 494 
members of Diptera ... 54 
Moss, composition of cushion of 328 
two generations of ... 330 
Mosses, and their allies . . . 328 
classified. 9 
general features.328 
habitat.328 
life history of.328 
number of. 9 
Moths, carriers of pollen ... 41 
example of Lepidoptera . . 39 
Moths and butterflies, field 
study of.44 
Motile cells (sperms) of moss 
plants.329 
Motion, a fundamental function 4 
Motor function of nerves . . 470 
Mouth, cavity of earthworm 181 
of man.404 
Movable joints.435 
