FIG. 17.—Diagram showing distribution of hot and cold spots on the back of the hand. C, cold
spots; H, hot spots.The Kinæsthetic Senses.—The muscles, tendons, and joints also give rise to
perfectly definite sensations, but they have not been named as have the
sensations from most of the other end-organs. Weight is the most clearly marked
of these sensations. It is through the sensations connected with movements of
muscles, tendons, and joints that we come to judge form, size, and distance.
The Organic Senses.—Finally, to the sensations mentioned so far must be
added those which come from the internal organs of the body. From the
alimentary canal we get the sensations of hunger, thirst, and nausea; from the
heart, lungs, and organs of sex come numerous well-defined but unnamed
sensations which play an important part in making up the feeling-tone of our
daily lives.
Thus we see that the senses may be looked upon as the sentries of the body,
standing at the outposts where nature and ourselves meet. They discover the
qualities of the various objects with which we come in contact and hand them
over to the mind in the form of sensations. And these sensations are the raw
material out of which we begin to construct our material environment. Only as
we are equipped with good organs of sense, especially good eyes and ears,
therefore, are we able to enter fully into the wonderful world about us and
receive the stimuli necessary to our thought and action.
4. PROBLEMS IN OBSERVATION AND INTROSPECTION
- Observe a schoolroom of children at work with the aim of discovering any