ACROMEGALY 253 



under the base of the skull and in part of the facial 

 skeleton, the explanation of which seems to be that no 

 infiltration of their texture is permitted on account of 

 their anatomical seclusion from the sensory and motor 

 nervature, or exclusion from the area of distribution of 

 the hypertrophic material, and of the natural attenuation 

 due to enlargement of these spaces on account of broaden- 

 ing and deepening of the osseous structures of the face ; 

 moreover, absorption, due to lateral and downward pres- 

 sure of the pituitary growth, more especially overtakes 

 the body of the sphenoid bone, reducing it, in many cases, 

 to a thin " vestige of itself." Further, and in like manner, 

 it may be said that the wasting and consequent asthenia 

 of the muscles of the limbs, as well as of the muscular 

 tissue of the heart and involuntary muscular tissues 

 generally, are due to the toxic, devitalising, and disinte- 

 grating influence exercised by the noxious cerebro-spinal 

 lymph exuded into their substance by the motor systemic 

 nerves. Likewise, the retrograde or degenerative optic 

 phenomena developed in the course of this disease are due 

 to the forward mechanical pressure of the enlarging gland 

 as it ploughs its malign way, rending and obliterating the 

 adjoining commissural nerve fibres of the optic chiasma 

 until their terminal special sense continuations wither and 

 die, shutting out and extinguishing the light of day from 

 its unfortunate subject for ever. The general cerebral and 

 mental changes observed in the progress of the disease 

 are also due, to a great extent, to the incidence of 

 mechanical pressure and the accumulation of effete matter, 

 and continue to extend with the widening boundaries of 

 the enlarging gland. From beginning to end, therefore, 

 an inevitable, although generally protracted, process of 

 centrifugal destruction and degenerative change char- 

 acterise the course of this disease, which at last overwhelms 

 and finally destroys piecemeal every vital organism and 

 function. In considering this subject a little more in 

 detail it has forced itself upon us that, in early embryonic 

 life, the surplus cerebro-spinal fluid and pituitary material 

 were disposed of by drainage through certain channels 

 left or laid down during early developmental processes 

 dating from before the time when the pharyngeal and hypo- 



