CAVERNOUS TUMOUES. 



163 



I call the way iii which the cavernous tumour is produced, a 

 ^'' cavernous metamorphosis." For I have arrived at the conclu- 

 sion, which might have been anticij^ated a 'priori^ that every vascular 

 tissue is suscej^tible of undergoing conversion into erectile tissue. 

 So far, therefore, the cavernous metamorphosis may be regarded 

 as a secondary phenomenon ; on the other hand, the intermediate 

 tissue-changes are so decidedly characteristic of morbid growth 

 that I cannot hesitate for a moment to place cavernous formations 

 among the histioid tumours. Inasmuch moreover, as the process 

 in question involves exactly the same tissue-changes as those 

 which underlie the development of fibromata, and as the caver- 

 nous tumour, when freed from its contained blood, presents all 



Fig. 52. 





% 



h^^ 



FuUy-dcveloped erectile tissue, -j^-^. From a cavernous tumour 

 of the orbit. 



the characters of a fibroid growth, I have chosen to deal with it 

 here rather than elsewhere. 



§ 130. It is difficult to get an insight into the mechanism of 

 a cavernous tumour. When any space contains a network or 

 system of trabeculae, that portion of the space which is not 

 actually occupied by the trabeculae themselves, must necessarily 

 form another network or trabecular system. If we distinguish 

 between a network and a parenchyma which occupies its meshes, 

 each of these constituents must stand in the relation of a paren- 

 chyma to its fellow. The transverse section of any trabecula of 

 one of the networks must bo identical with the circumference of 

 an islet of parenchyma as regards the other network, and vice 

 versCu Fibres which in one of the two networks surround the 



