460 MOVEMENTS VOICE AND SPEECH. 



CHAPTER XV. 



MOVEMENTS VOICE AND SPEECH. 



Amorphous contractile substance and amoeboid movements Ciliary movements Movements due to elas- 

 ticity Elastic tissue Muscular movements Physiological anatomy of the involuntary muscular : 

 Contraction of the involuntary muscular tissue Physiological anatomy of the voluntary muscular 

 tissue Connective tissue Connection of the muscles with the tendons Chemical composition of the 

 muscles Physiological properties of the muscles Muscular contractility, or excitability Muscular 

 contraction Electric phenomena in muscles Muscular effort Passive organs of locomotion Physio 

 logical anatomy of the bones Physiological anatomy of cartilage Voice and speech Sketch of the 

 physiological anatomy of the vocal organs Mechanism of the production of the voice Laryngeal 

 mechanism of the vocal registers Mechanism of speech The phonograph. 



THE various processes connected with the nutrition of animals involve 

 certain movements ; and almost all animals possess in addition the" power 

 of locomotion. Many of these movements have of necessity been considered 

 in connection with the different functions ; as the action of the heart and 

 vessels in the circulation, the uses of the muscles in respiration, the ciliary 

 movements in the air-passages, the muscular acts in deglutition, the peri- 

 staltic movements and the mechanism of defsecation and urination. There 

 remain, however, certain general facts with regard to various kinds of move- 

 ment and the mode of action of the different varieties of muscular tissue, 

 that will demand more or less extended consideration. As regards the varied 

 arid complex acts concerned in locomotion, it is difficult to fix a limit between 

 anatomy and physiology. A full comprehension of such movements should 

 be preceded by a complete descriptive anatomical account of the passive and 

 active organs of locomotion ; and special treatises on anatomy give the uses 

 and actions as well as the structure and relations of these parts. 



Amorphous Contractile Substance and Amoeboid Movements. In some of 

 the lowest forms of beings, in which hardly any thing but amorphous mat- 

 ter and a few granules can be recog- 

 nized by the microscope, certain 

 movements of elongation and retrac- 

 tion of their amorphous substance 

 have been observed. In the higher 

 animals, similar movements have 

 been noticed in certain of their struct- 

 ures, such as the leucocytes, the con- 



FIG. 142. Amoeba diffluens, changing inform and -ITT 



moving in the direction indicated by the ar- tents 01 the OVUH1, epithelial cells and 

 row (Longet). | 



connective-tissue cells. These move- 

 ments generally are simple changes in the form of the cell, nucleus, or what- 

 ever it may be. They depend upon an organic principle formerly called sar- 

 code and now known as protoplasm ; but it is not known that such move- 

 ments are characteristic of any one definite constituent of the body, nor is it 

 easy to determine their cause and their physiological importance. In the 

 anatomical elements of adult animals of the higher classes, these movements 

 usually appear slow and gradual, even when viewed with high magnifying 

 powers; but in some of the very lowest forms of life, these movements 



