ORIGIN A TION OF NE W CENTRES. 2 1 3 



material, its nucleus growing larger and taking its place. 

 The original nudeolus in this case becomes the nucleus, and 

 new nucleoli make their appearance in what was the original 

 nucleolus. The whole process consists of evolution from 

 centres , and the production of new centres within pre-existing 

 centres a process not comparable with any known physical 

 change, but peculiar to and characteristic of the living 

 world. Zones of colour, of different intensity, are often 

 observed in a cell coloured with carmine ; the outermost or 

 oldest, or that part which is losing its vital power, and 

 becoming converted into formed material, being very slightly 

 coloured, the most central part, or the nucleus, although 

 furthest from the colouring solution, exhibiting the greatest 

 intensity of colour. These points are well illustrated in 

 PL VII, fig. 4, and some other figures, which have been 

 carefully copied from well-prepared specimens. 



Bioplasm, in a comparatively quiescent state, is not un- 

 frequently entirely destitute of nuclei, but these bodies may 

 make their appearance if the mass be more freely supplied 

 with nutrient matter. This fact is to be noticed in the case 

 of the connective tissue corpuscles, as well as the masses of 

 bioplasm connected with the walls of vessels, nerves, 

 muscular tissue, epithelium, &c., which often exhibit no 

 nuclei (or according to some, nucleoli), when these tissues 

 become supplied with an increased quantity of pabulum, as 

 occurs in all cases of inflammation. I have demonstrated 

 the important fact that several small nucleoli are very 

 rapidly developed in all parts of the bioplasm of the tissue 

 in all forms of fever and inflammation. (PI. XI, fig. n.) 

 Numerous nucleoli have been demonstrated in the bio- 

 plasm of some of the above-mentioned tissues within twenty- 



