A Civic Biology, Presented in Problems

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Plants and Animals mutually Helpful.--Most plants and animals stand in an attitude of mutual helpfulness to one another, plants providing food and shelter for animals; animals g...

Egg and Larva.--The eggs, tiny hat-shaped dots a twentieth of an inch in length, are fastened singly to the underside of milkweed leaves. Some wonderful instinct leads the anima...

Hunter, _Laboratory Problems in Civic Biology_. American Book Company. Andrews, _A Practical Course in Botany_, pages 214-249. American Book Company. Atkinson, _First Studies of...

_Laboratory exercise._--Examination of bean in pod. Examination and identification of parts of bean seed. _Laboratory demonstration._--Tests for the nutrients: starch, fats or o...

_Problem.--What a plant takes from the soil and how it gets it._ _(a) What determines the direction of growth of roots?_ _(b) How is the root built?_ _(d) What is in the soil th...

_Problem.--Where, when, and how do green plants make food?_ _(a) How and why is moisture given off from leaves?_ _(b) What is the reaction of leaves to light?_ _(c) What is made...

In the wood will be noticed (see Figure) a number of lines radiating outward from the pith toward the bark. These are thin plates of pith which separate the wood into a number o...

_By Fire._--Indirectly, man is responsible for fire, one of the greatest enemies of the forest. Most of the great forest fires of recent years, the losses from which total in th...

_Problems.--(a) How molds and other saprophytic fungi do harm to man._ _(b) What yeasts do for mankind._ _(c) A study of bacteria with reference to_ _(1) Conditions favorable an...

Size and Form.--In size, bacteria are the most minute plants known. A bacterium of average size is about 1/10000 of an inch in length, and perhaps 1/50000 of an inch in diameter...

Typhoid Fever.--One of the most common germ diseases in this country and Europe is typhoid fever. This is a disease which is conveyed by means of water and food, especially milk...

Reproduction of Paramoecium.--Sometimes a paramoecium may be found in the act of dividing by the process known as _fission_, to form two new cells, each of which contains half o...

III. Coelenterates.--The hydra and its salt-water allies, the jellyfish, hydroids, and corals, belong to a group of animals known as the _Coelenterata_. The word "coelenterate"...

Special home laboratory reports may be well made at this time, for example: determination at a local fish market of the fish that are cheap and fresh at a given time. Have the s...

During the outbreak of Rocky Mountain locusts in Nebraska in 1874-1877, Professor Samuel Aughey saw a long-billed marsh wren carry thirty locusts to her young in an hour. At thi...

The Typhoid Fly a Pest.--The common fly is recognized as a pest the world over. Flies have long been known to spoil food through their filthy habits, but it is more recently tha...

Circulation of the Blood.--In the vertebrate animals the blood is said to circulate in the body, because it passes through a more or less closed system of tubes in its course ar...

_Laboratory exercise._--On variation and heredity among members of a class in the schoolroom. _Laboratory exercise._--On construction of curve of variation in measurements from...

In 1667 Elizabeth Tuttle, "of strong will, and of extreme intellectual vigor, married Richard Edwards of Hartford, Conn., a man of high repute and great erudition. From their on...

Fuel Values of Nutrients.--In experiments performed by Professor Atwater and others, and in the appended tables, the value of food as a source of energy is stated in heat units...

Is Alcohol a Food?--The question of the use of alcohol has been of late years a matter of absorbing interest and importance among physiologists. A few years ago Dr. Atwater perf...

The Teeth.--In man the teeth, unlike those of the frog, are used in the mechanical preparation of the food for digestion. Instead of holding prey, they crush, grind, or tear foo...

Footnote 45: This change is due to the action of certain enzymes upon the nutrients in various foods. But we also find that peptones are changed back again to proteins when once...

The Effect of Exercise on the Circulation.--It is a fact familiar to all that the heart beats more violently and quickly when we are doing hard work than when we are resting. Co...

Exercise should always be limited by fatigue, which brings with it fatigue poisons. This is nature's signal when to rest. If one's use of diet and air is proper, the fatigue poi...

The Brain of Man.--In man, the central nervous system consists of a brain and spinal cord inclosed in a bony case. From the brain, twelve pairs of nerves are given off; thirty-o...

Effect on the Organs of Special Sense.--Professor Forel, one of the foremost European experts on the question of the effect of alcohol on the nervous system, says: "Through all...

School Surroundings.--How to Improve Them.--From five to six hours a day for forty weeks is spent by the average boy or girl in the schoolroom. It is part of our environment and...

The following figures show the differences between number of cases and mortality in the army in 1898 during the war with Spain and in 1911 during the concentration of certain of...

Associated with Darwin's name we must place two other co-workers on heredity and evolution, Alfred Russel Wallace, an Englishman who independently and at about the same time rea...

Twelfth week. DIGESTION. The alimentary canal of frog and of man compared. Drawings. (One day.) The work of glands. Work of salivary gland. Enzymes, internal secretions. Experim...

Ear, section, |359|. Echinoderms, 184. Economic value of green plants, 117; importance of spawning habits of fishes, 239. Ectoderm, 177. Effect of light on leaves, 88. Efficienc...