252 PHYSIC 



transmission, or circulation, become more or less organised 

 substances in, and around, the invaded textures and 

 organs ; hence, an explanation of the apparent enigma, 

 of the association of disease of the pituitary body with the 

 enlargement of bones, and a pachydermatous condition of 

 skin, is thus afforded on definite anatomical and histo- 

 logical lines ; an explanation, moreover, which should be 

 fruitful in suggesting the lines along which clinical research 

 may be most profitably conducted, and relief or cure 

 secured, for a hitherto almost hopeless disease. 



Thus, the overflowing, now pathological, cerebro-spinal 

 fluid, circulating along the afferent or peripheral nerves, 

 deposits in and amongst the cutaneous textural elements 

 whatever portion of its more solid constituents as refuses 

 to pass through the sweat glands, sudoriferous and 

 sebaceous, with the inevitable result of thickening or 

 hypertrophy of the skin. Thus, likewise, does the con- 

 taminated cerebro-spinal fluid, on reaching the periosteum 

 of the bones to which the various muscles of the body 

 and limbs are attached, and to which the motor or efferent 

 nerves are distributed, deposit its more solid constituents 

 on the surface and within the texture of these bones, with 

 the results of thickening and lengthening of the shafts 

 of the limb bones and obliteration of the cancellous inter- 

 spaces of such osseous structures as the spinous processes 

 of the vertebrae, along with the gross enlargement of the 

 points and surfaces of attachment of the various muscles. 

 Thus, also, do the Pacchionian bodies account for invasion 

 of the diploe of the bones of the cranium, the obliteration 

 of their cancellous structure, and the universal or local 

 thickening of the whole calvarium, except what has been 

 produced externally where the various muscles are attached 

 through the motor nerves supplying these muscles. Be- 

 sides these somewhat general hyperostotic effects of the 

 disease on the skeleton, sequestered bony deposits are 

 found attached or lying close to certain bones, or developed 

 on or within the muscle sheaths and in connection with 

 their tendonous continuations. A curious departure from 

 the general hypertrophic progress characterising the disease 

 is observed in the thinning of the bony walls of the 

 pneumatic or air-spaces so plentifully developed along and 



