FIBRE-CELLS, ETC. 127 



It had a gray and translucent appearance, exhibited no elas- 

 ticity, and when examined with the microscope, presented no 

 trace of its future structure. A gray cord, indistinctly marked 

 with longitudinal fibres, was seen, in which a great many 

 cell-nuclei might be recognized. I did not prosecute any fur- 

 ther researches, as the presence of the nuclei was sufficient 

 proof that there was nothing essentially different in the type 

 of its formation. 



On casting a retrospective glance over the class of fibre- 

 cells which we have just been considering, we find that it 

 forms a very natural and somewhat strictly defined group 

 amongst the tissues. The tissues comprised in it are generated 

 from nucleated cells, which are transformed into fasciculi of 

 fibres by elongation, in the first place, and by the splitting of 

 the bodies of the cells themselves into separate fibres at a sub- 

 sequent period. The fundamental phenomenon previously 

 described at page 39 is distinctly presented in the formation 

 of these cells ; a structureless, gelatiniform mass, the cytoblas- 

 tema, is first present, and lies outside the cells already formed. 

 The cells are developed in this, the nucleus being, in all pro- 

 bability, the earliest formation. The growth of the cells 

 proceeds, and they become transformed into fibres in the 

 manner described. The quantity of the cytoblastema con- 

 tinually diminishes in proportion to the cells or fibres which 

 are forming, but probably part of it remains persistent be- 

 tween the fibres throughout the whole of life j in the mature 

 condition, however, it exists in greater quantity in areolar than 

 in fibrous or elastic tissue. 



The mode of generation teaches us which parts of these 

 tissues correspond to the constituents of those hitherto treated 

 of. The elementary cells of areolar tissue, before undergoing 

 change, correspond morphologically with the cartilage and 

 epithelium-cells, the mucus-corpuscles, &c. ; and as a fasciculus 

 of fibres is generated from each cell of areolar tissue, a whole 

 fasciculus of fibres of areolar tissue accordingly corresponds to 

 what was an individual cartilage- or epithelium-cell, in the pre- 

 vious classes. The structureless cytoblastema between the 

 fibres of areolar tissue corresponds, however, to the firm inter- 

 cellular substance, forming the principal mass of most cartilages, 



