208 
DR, F. SEMON xiND MR. V. HORSLEY ON AN INVESTIGATION 
.species of animal in the representation in the nervous system of respiration and 
phonation respectively. 
The need for efficient respiratory action on the part both of the larynx and the 
thorax is much greater in the young'er animal than in the adult, and is greater, as 
Legallois more esj^ecially has shown, in the Cat and the Horse than in any other 
animal, especially more than in the Dog. The present part of oiu’ paper will be 
devoted to summarising the facts that we liave observed and the differences noted 
according to the age of the animal, and we shall group the results, as before, according 
to the species, beginning again witli tlie highest. 
(a.) Monkeij .—In the Monkey we have only incomplete observations owing to the 
difficulty of obtaining many Monkeys, but all our observations went to show tha.t 
phonatory adduction was less represented in the young animal than in the older adult. 
{h.) Dog .—In the Dog these differences are also marked. In the young Dog even 
with strong currents we have frequently only obtained from the focus of laryngeal 
phonatory representation a high degree of acceleration of respiration with marked 
diminution of abduction, but no complete adduction ; in fact in the cortex of such an 
animal, while respiration is most efficiently represented, phonation is only imperfectly 
evolved. 
(c.) Cat .—In the Cat, again, the same thing prevails in its entirety, with the 
additional point, viz., that this want of differentiation in the laryngeal movements 
was not confined to the larynx, but also prevailed in the centres for the movements of 
the limbs. 
It is in accordance with points noticed by one of us (V. H.) in the representation 
of the limb-muscles in the cortex of the Monkey that a wider extent of cortex 
provides for a higher evolution or development of the motor representation, and 
probably the differences we have just been describing as produced by age are due to 
the greater or less provision of cortical mateiial for subserving the particular function 
represented. 
Conclusions. 
The conclusions which we feel may legitimately be drawn from the foregoing 
experiments—and which, we may be permitted to add, are based not only upon the 
results of the work just described, but also upon much winch we have not alluded to, 
and which will be desci'ibed in subsequent communications—may best be put forward 
upon the plan according to which we believe the central innervation of the laryngeal 
movements is arranged. 
In consequence of the laryngeal muscles serving, as particularly insisted upon by 
one of us (F.S.), in this connection, two distinct functions (1) phonation, (2) respi¬ 
ration, and in consequence of these two functions being, one connected with so-called 
purposive or volitionary acts, the other, on the contrary, related to those functions 
