604 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1914. 
bonds of coordination required for ordinary speech; but a little search 
into the matter will show anyone that we are here in contact with one 
of the most incredible marvels in nature. Most wonderful of all, the 
whole mechanism is, from an evolutionary standpoint, quite new— 
a product of merely the later fragment of a brief geological period! 
When we consider the number of movements, following one another 
in continually varying order, required for articulate speech, it is 
obvious that only machinery which is able to act with every me- 
chanical advantage and with a minimum of friction can accomplish 
such a task with precision. Public speakers frequently talk at the 
rate of 150 words a minute, while it seems possible to articulate quite 
clearly and correctly when speaking at the rate of 180 words a minute. 
If we analyze the action of the tongue when speaking at the rate of 
150 words a minute, we find that there must be at least 500 different 
movements or adjustments. This gives 8 or 9 in every second! 
Such movements, it must be remembered, do not follow one another 
regularly in mechanical rotation like the piston-beats of a multiple- 
cylindered engine, but are continually varying their order. What 
wonder is it that coordination sometimes breaks down, with the 
result of a stutter or a stammer ? 
Now a brief examination of the intrinsic muscles of the tongue, 
i. e., those that begin and end in the tongue itself like the distal 
muscles of an elephant’s trunk, will show how totally inadequate 
these would be to produce any such result; but immediately one takes 
careful note of the mode of action of the genio-glossus muscle the 
solution of the tongue’s incredible agility becomes possible. 
It is seen in the accompanying diagrams (see figs. 72-76) that the 
several bundles, or fasciculi, of the muscle are able to act more or 
less at right angles to the main plane of the tongue without any- 
thing to hamper them. For each flashlike movement of the tongue 
away from the palate all that is demanded is an instantaneous 
shortening of one or other of these independent strips. or instance, 
in pronouncing the letter T we place the tip of the tongue against the 
palate close to the upper incisor teeth (see fig. 75), and then snatch 
it away with great rapidity. The placing it there is probably the 
work of the intrinsic muscle called the superior longitudinal lingual, 
but the more critical action of withdrawing it at the proper moment 
is due to the front fibers of the genio-glossus, which become taut and 
braced for instantaneous action as soon as the tongue-tip is pressed 
against the palate. 
In figure 74 it is seen that in the hard G or K exactly the same 
thing takes place with the central fasciculi of the muscle. A like 
action comes in with sounds involving L, N, R, D, J, Q; while in 
S, X, and all other consonants where the nice adjustment of the 
distance of the tongue from the palate is a matter of moment the 
