SOLITARY TUBERCLES OF THE BRAIN. 523 



a Borsdorf apple,* as for example in the brain those 

 are not simple tubercles. You will generally find the 

 tubercles in the brain described as being solitary, but 

 they are not simple bodies ; every such mass (tuber) 

 which is as large as an apple, or even not larger than a 

 walnut, contains many thousands of tubercles ; it is quite 

 a nest of them which enlarges, not by the growth of the 

 original focus (granule), but rather by the continual for- 

 mation and adjunction of new foci (granules) at its cir- 

 cumference. If we examine one of these perfectly yel- 

 lowish white, dry, cheesy tubera, we find immediately 

 surrounding it a soft, vascular layer which marks it off 

 from the adjoining cerebral substance a closely invest- 1 

 ing areola of connective tissue and vessels. In this layer 

 lie the small, young granules, now in greater, now in 

 less, number. They establish themselves externally [to 

 the previously existing ones] and the large tuber grows 

 by the continual apposition of new granules (tubercles), 

 of which every one singly becomes cheesy j the whole 

 mass, therefore, cannot in its entirety be regarded as a 

 simple tubercle. The tubercles themselves remain really 

 minute, or as we are wont to say, miliary. Even when 

 on the pleura, by the side of quite small granules, large 

 yellow plates, looking as if they were deposited upon the 

 surface, are met with, these too are not simple tubercles, 

 but masses composed of a large aggregate of originally 

 separate granules. 



Here, you see, form and nature are in reality insepara- 

 bly connected. The form is produced by the growth of 

 the tubercle from single cells of connective tissue, by the 

 degenerative proliferation of single groups of connective- 

 tissue corpuscles. Thus, without more ado, it appears 



* Borsdolf apples are very constant in their size, and measure from an inch and a 

 half to an inch and three quarters (!" 1J") in diameter. From a MS. Note by 

 the Author. 



