CONNECTIVE TISSUE. 



179 



very closely resembles the epithelial tissue, except that 

 the intervals between the nuclei are wider, and that the 

 substance in which they are imbedded cannot be broken 

 up into a separate cell-body for each nucleus. In the 

 second form (fig. 51, A) the matrix exhibits fine wavy 

 parallel lines, as if it were marked out into imperfect 



Fig. 51. — Astacus fluviatilis. — Connective tissue ; A, second form ; S, 

 third form, a, cavities ; n, nuclei. H'ghly magnified. 



fibres. In this form, as in the next to be described, 

 more or less spherical cavities, which contain a clear 

 fluid, are excavated in the matrix ; and the number of 



