ATHEROMATOUS CYSTS. 391 



by the accumulated secretions till it reaches the size of a 

 pigeon's egg, or even a child's fist. It becomes a retention-cyst, 

 in which we are able to distinguish between a secreting cyst- 

 wall and secreted contents. The former is composed of a 

 connective tissue rich in cells, lined by from two to three layers 

 of pavement epithelium. Its thickness is in inverse proportion 

 to the size of the tumour ; it may ultimately become as thin as a 

 serous membrane. Nevertheless we must always regard it as u 

 hyperplastic product, inasmuch as the sac of connective tissue 

 in which it originated, is the thinnest of all the layers and 

 sheaths of the hair-follicle. This sac must therefore have 

 undergone a striking increase, both in superficial area and in 

 thickness : and althouo;h I am far from wishin(T to assert that 

 this increase in size is the cause of the over-secretion and reten- 

 tion, it nevertheless seems to me a very important fact, that in 

 proportion to the gradual increase in the production of epi- 

 thelium, the area, not only of the epithelial layer itself, but that 

 of the organ which I regard as the matrix of the epithelium, 

 has also undergone an increase. Moreover it is clear that the 

 increased production of epithelium is at once the cause and the 

 consequence of the dilatation of the folHcle, the case falling 

 nnder the category of those circles of cause and effect with 

 which we are familiar in the pathology of physiological cysts, 

 e.gf. the urinary and gall-bladders. The contents of the cyst are 

 now friable and greasy, now more honey-like, now a stiffl}" 

 gelatinous, transparent and concentrically laminated mass. On 

 one occasion I came across a cyst which admirably illustrated 

 the popular German name of GrutzheuteJgescliiculst. In a thin 

 fluid like the yolk of a raw egg, a number of grey, translucent 

 granules, not unlike boiled groats, were suspended. All athero- 

 matous cysts of any size usually contain cholesterin in large 

 quantities, which gives the grueliy matter a spangled lustre. 

 The microscope shows us that all matters resembling boiled 

 groats or jelly, all the white, friable contents of the cyst, are 

 made up of epidermic cells in a partial state of fatty degeneration. 

 The yellow constituents are granule-cells and oily debris; the 

 glittering scales, as has been already stated, are cholcsterin- 

 plates. We sometimes find a certain number of fine lanugo- 

 hairs ; these have obviously grown either from pre-existing oj* 

 from newly-formed hair-roots. Upon the whole, the hair is 



