DESCRIPTION OF THE PLATES, 



CENTRES OF NUTRITION- 



PLATE I. Fig. 1. A portion of the middle and internal membranes 

 of a large encysted tumour situated under the 

 tongue, and removed by Professor Syme. 

 a The middle or second membrane, which is a 

 germinal membrane, consisting of flattened cells, 

 the lines of junction of which are faintly visible, 

 the nuclei remaining as the germinal spots of 

 the membrane. 



b The internal membrane, a layer of small cells, 

 somewhat spherical, with slightly granular con- 

 tents. 



The external membrane of the cyst, consisting 

 of areolar and elastic fibres, contained the blood- 

 vessels of the morbid growth. 



The cyst contained a sx>ft mass resembling 

 thick honey in consistence. The outer layer of 

 this mass was white, and consisted of large, flat 

 transparent cells or scales, with few or no traces 

 of nuclei. The larger internal part of the mass 

 was reddish grey, and consisted of ovoidal cells, 

 resembling those of the external layer, except 

 that they were turgid with a transparent oily- 

 like fluid, and contained nuclei in various stages 

 of developement. 



