and Laboratory Methods 2545 



Let us now see how much we can learn of the anatomy and physiology of the 

 human arm and hand by simple observation and experiment. One can easily 

 feel through the fiesh and determine that the skeleton of the upper arm is formed 

 of one long bone which has an enlargement at either end. The two bones of 

 the forearm can also be distinguished and described. We cannot of course 

 count the small bones of the wrist, but the range of motion between them can 

 be shown easily. In the palm and fingers the position and shape of the bones 

 can be determined almost as well as by studying a prepared skeleton. Having 

 learned all that is possible from his own arm, the pupil's attention should be 

 directed to a study of an articulated skeleton. And before any text-book lesson 

 is assigned on a given set of bones, the bones should be pointed out by the pupil 

 on his own body, or on the skeleton, and their form and use studied. 



The position and action of the muscles of the arm are even more easily deter- 

 mined. Why should a boy learn from a book that his biceps muscle on contract- 

 ing becomes harder, thicker, and shorter, when by a few laboratory directions 

 he can so clearly demonstrate this fact ? He can make out, too, that the lower 

 tendon of this muscle is attached in the region of the forearm, and after grasping 

 this tendon between the thumb and forefinger, he can by turning the forearm 

 satisfy himself that this muscle is joined to the radius and not to the ulna. A 

 similar study of the fleshy part of the forearm reveals to the pupil that the 

 muscles of the fingers are located in this region. By closing and opening the 

 fingers the long tendons which pull on the fingers can be traced from the fore- 

 arm, along the wrist and the palm or back of the hand to the bones in the digits. 

 One can easily see how clumsy would be the hand were all the flexor 

 muscles of the fingers located in the palm, as the flexors of the thumb are. 



The essential points in the structure of the skin, of the nails and the hair, of 

 the action of the blood-vessels, sweat glands, and nerves in the hand can also be 

 found out by the individual pupil. It may seem to take a bit longer to acquire 

 these facts by observation than from text-book lessons. But that the laboratory 

 method of study is far the better is clear from the interest manifested by the 

 pupil in carrying on his work, from the greater clearness with which he can 

 describe what he has learned, and from the fact that he can in a moment's time, 

 even when writing an examination paper, test the accuracy of his statements by 

 a repetition of his original observations. It is amusing at times to watch a class 

 while taking its final test in physiology. If anyone who had not watched the 

 laboratory work through the term should enter the examination room, he would 

 be at a loss to interpret the apparent contortions of the muscles, joints, and 

 other organs of the pupil's body. 



There is no time to suggest some of the interesting and instructive labora- 

 toiy experiments which can be used to make clear the processes of digestion, 

 circulation, respiration, and sensation. When possible, these experiments should 

 be performed by each pupil on his own body. If models and pieces of apparatus 

 are to be used instead, they should be as simple in their action as possible, and 

 attention should always be called to the fact that no model can be made to work 

 exactly like the living organs and tissues. 



We have now briefly discussed some of the experimental work that is possible 



