Page:Philosophical Transactions - Volume 096.djvu/217

202 to understand the nature of a disease, which It was not possible we could have a correct idea of, when we were ignorant of the existence of the part in which it takes place. It not only explains the situation of the tumour, the want of connection with the body of the gland, and the narrowness of its base where that is met with, but it solves what has ever appeared to me the greatest difficulty, how it should protrude into the cavity of the bladder. This arises from the hard substance of the coats of the vasa deferentia being in close contact, and bound down upon this lobe, so that from its first enlargement it must immediately press up the inner membrane of the bladder, which can make very little resistance.

This lobe of the prostate gland, from its situation and connection with the vasa deferentia, is liable to many causes of swelling, which the body of the gland itself is free from; for every irritation upon the seminal vessels or their orifices may be communicated to it by continuity of parts: and aged men, from an ignorance of these facts, are too often, through imprudence, producing an excitement in those vessels which the parts are unable to support; and when this is long continued, inflammation becomes the consequence, which cannot take place to any degree without being communicated to this lobe, and producing an enlargement of it.

Every violent effort which is made to empty the urinary bladder produces an unusual pressure against this lobe, by which it may be injured. There is also much reason for believing, that the diseased state of the lateral parts of the gland, so very commonly met with in the latter period of life, has its origin in this particular lobe; since in most of the cases of a diseased state of the gland, which have come under my observation after deaths this lobe has been enlarged in a