First course in biology

If the course in biology begins in the fall (with the school year), it may be well to study plant biology two days in the week and animal biology three days until midwinter; whe...

These experiments are inserted for those pupils who have not had instruction in chemistry and physics, to give them a point of view on the subjects that follow. At least a gener...

If one compares _any two plants_ of the same kind ever so closely, it will be found that they _differ from each other_. The difference is apparent in size, form, color, mode of...

No two plants or parts of plants are identically exposed to the conditions in which they live. The large branches in Fig. 1 probably had more room and a better exposure to light...

The plants that most perfectly meet their conditions are able to persist. _They perpetuate themselves._ Their offspring are likely to inherit some of the attributes that enabled...

In the long course of time in which plants have been accommodating themselves to the varying conditions in which they are obliged to grow, _they have become adapted to every dif...

=The Parts of a Plant.=--Our familiar plants are made up of several distinct parts. The most prominent of these parts are _root_, _stem_, _leaf_, _flower_, _fruit_, _and seed_....

The seed contains a _miniature plant_, or =embryo=. The embryo usually has three parts that have received names: the stemlet, or =caulicle=; the seed-leaf, or =cotyledon= (usual...

The entire mass of roots of any plant is called its =root system=. The root system may be annual, biennial or perennial, herbaceous or woody, deep or shallow, large or small.

=The function of roots is twofold=,--to provide _support or anchorage_ for the plant, and to _collect and convey food_ materials. The first function is considered in Chapter VII...

=The Stem System.=--The stem of a plant is the part that _bears the buds_, _leaves_, _flowers_, _and fruits_. Its office is _to hold these parts up to the light and air_; and th...

There are two main types of stem structure in flowering plants, the differences being based on the arrangement of bundles or strands of tissue. These types are _endogenous_ and...

Leaves may be studied from four points of view,--with reference (1) to their _kinds_ and _shapes_; (2) their _position_, or _arrangement_ on the plant; (3) their _anatomy_, or _...

Besides the =framework=, or system of veins found in blades of all leaves, there is a soft cellular tissue called =mesophyll=, or =leaf parenchyma=, and an =epidermis= or skin t...

We have discussed (in Chap. VIII) the work or function of roots and also (in Chap. X) the function of stems. We are now ready to complete the view of the main vital activities o...

Thus far we have spoken of plants with roots and foliage and that depend on themselves. They collect the raw materials and make them over into assimilable food. They are =indepe...

=A bud is a growing point=, terminating an axis either long or short, or being the starting point of an axis. _All branches spring from buds._ In the growing season the bud is a...

We have learned (in Chap. VI) that plants propagate by means of seeds. _They also propagate by means of bud parts,--as rootstocks (rhizomes), roots, runners, layers, bulbs._ The...

We have found that plants struggle or contend for a place in which to live. Some of them become adapted to grow in the forest shade, others to grow on other plants, as epiphytes...

The function of the flower is to _produce seed_. It is probable that all its varied forms and colors contribute to this supreme end. These forms and colors please the human fanc...

=Fertilization.=--_Seeds result from the union of two elements or parts._ One of these elements is a cell-nucleus of the pollen-grain. The other element is the cell-nucleus of a...

=Origin of the Flower-cluster.=--We have seen that branches arise from the axils of leaves. Sometimes the leaves may be reduced to bracts and yet branches are borne in their axi...

The ripened ovary, with its attachments, is known as the =fruit=. _It contains the seeds._ If the pistil is simple, or of one carpel, the fruit also will have one compartment. I...

It is to the plant’s advantage to have its seeds distributed as widely as possible. _It has a better chance of surviving in the struggle for existence._ It gets away from compet...

The plants thus far studied produce flowers; and the flowers produce =seeds= by means of which the plant is propagated. There are other plants, however, that produce no seeds, a...

The pupil who has acquired skill in the use of the compound microscope may desire to make more extended excursions into the cryptogamous orders. The following plants have been c...

Biology (Greek, _bios_, life; _logos_, discourse) means the science of life. It treats of animals and plants. That branch of biology which treats of animals is called _zoology_...

SUGGESTIONS.--Amebas live on the slime found on submerged stems and leaves in standing water, or in the ooze at the bottom. Water plants may be crowded into a glass dish and all...

SUGGESTIONS.--In many parts of the United States, fresh-water sponges may, by careful searching, be found growing on rocks and logs in clear water. They are brown, creamy, or gr...

SUGGESTIONS.--Except in the drier regions of the United States, the hydra can usually be found by careful search in fresh water ponds not too stagnant. It is found attached to s...

SUGGESTIONS. Since the echinoderms are aberrant though interesting forms not in the regular line of development of animals, this chapter may be omitted if it is desired to short...

SUGGESTIONS:--Earthworms may be found in the daytime after a heavy rain, or by digging or turning over planks, logs, etc., in damp places. They may be found on the surface at ni...

SUGGESTIONS.--In regions where crawfish are not found, a live crab may be used. Locomotion and behavior may be studied by providing a tub of water, or better, a large glass jar...

SUGGESTIONS.--Collect grasshoppers, both young and full-grown, and keep alive in broad bottles or tumblers and feed on fresh grass or lettuce. When handling a live grasshopper,...

SUGGESTIONS.--The mussel is usually easy to procure from streams and lakes by raking or dredging. In cities the hard-shelled clam, or quahog, is for sale at the markets, and the...

SUGGESTIONS.--The behavior of a live fish in clear water, preferably in a glass vessel or an aquarium, should be studied. A skeleton may be prepared by placing a fish in the rea...

The theory of evolution teaches that animal life began in a very simple form in the sea, and that afterward the higher sea animals lost their gills and developed lungs and legs...

This =class= is divided into _four orders_ which have such marked differences of external form that there is no difficulty in distinguishing them. These orders are represented b...

SUGGESTIONS.--The domestic pigeon, the =fowl=, and the English sparrow are most commonly within the reach of students. The last bird has become a pest and is almost the only bir...

SUGGESTIONS.--A tame rabbit, a house cat, or a pet squirrel may be taken to the school and observed by the class. Domestic animals may be observed at home and on the street. A s...

To which _branch_ of animals does man belong? To which _class_ and _order_ in that branch? (Animal Biology, pages 125, 193.) There is no other animal _species in the same genus...

NOTE TO TEACHER.--The experiments should be assigned in turn to the pupils as each chapter is reached: _e.g._ this set of 13 will leave 3 pupils in a class of 39 to stand respon...

_Experiment 1._ (At home.) =Is the Arch of the Foot Elastic?=--Wet the foot in a basin of water and, while sitting, place the foot flat upon a piece of paper. Draw the outline o...

It has already been stated that there are at least two muscles attached to a bone to move it in opposite directions. Since there are two hundred and six bones, you are not surpr...

_Experiment 1._ =Anatomy of Mammalian Heart.=--Get a sheep’s or beef’s heart from the butcher. Get the whole heart, not simply the ventricles (as usually sold). Note the blood v...

_Experiment 1._ (Home.) =Study of the Throat.=--Sit with the back to the light. Study the open mouth and throat with a mirror and make out the uvula, tonsils, and other parts sh...

_Experiment 6._ =Human Teeth.=--Study the form of teeth from every part of the mouth. Get a handful from a dentist. Break some of the teeth to make out their structure. Classify...

=Review Questions introducing this Subject.=--What is a cell? What are the five supporting tissues? What are the two master tissues? Why are they so called? What kind of cells h...

_Experiment 1._ =Where are the Nerves of Touch most Abundant?=--Open a pair of scissors so that the points are one eighth of an inch apart, and touch both points to the tip of t...

_Experiment 2._ =Fermentation.=--Put a tablespoonful of sugar into this water and set the glass in a warm place for a day or two. Do you see any bubbles of gas? Have the odor an...

Page I xvii: [See also experiments with candle and breath, in Introduction to Human Biology.] and related hyperlinks changed to [See also experiments with candle and breath, in...