38 



GENERAL PART. 



phora). The so-called secreted tissue of young Ctenophora, and the 

 gelatinous tissue of Medusae and Echinoderm larvse, into which cells 

 eventually migrate, being at first absent, has a similar relation 

 (fig. 26). 



FIG. 26. Gelatinous tissue of Rhizostorua. F, fibrous network ; Z, cells with processes ; 



Z', the same in division. 



Reticular connective tissue consists of a network of star-shaped 

 and branched cells, the spaces of which contain another kind of 

 tissue element. In the so-called adenoid tissue, which functions as 

 the supporting tissue of the lymph glands, the contents of the inter- 

 cellular spaces are lymph corpuscles. 



A form of connective 

 tissue very widely scat- 

 tered amongst the Ver- 

 tebrates is the so-called 

 'Jihrillar connective tissue 

 (fig. 27). This consists 

 of a large proportion 

 of spindle-shaped, or 

 ;ilso branched cells, and 

 of a ^olid intercellular 

 substance, totally or par- 

 tially broken up into 

 bundles of fibres, which 



PIG. 27. Fibril] ar connective tissue. 



possesses the property of 



yielding gelatine on boiling. If the protoplasm of the cells is mostly 

 or entirely used up in the formation of fibres, fibrous tissue is produced 

 with nuclei in the position of the original cells. Very often the 



