CONNECTIVE TISSUE. 45 



directions. The corneal cells, which are the most promi- 

 nent objects in the specimen, are seen thickly scattered 

 over the field, stained of a reddish-violet color. They 

 have flat, irregular-shaped bodies which send off a varia- 

 ble number of longer and shorter processes ; the nuclei 

 are large, ovoidal, or irregular-shaped, and usually con- 

 tain nucleoli. Fine irregular-branching, almost linear 

 structures are seen in good preparations thickly scattered 

 over the specimen, and very frequently lying nearly at 

 right angles to one another. A part at least of these are 

 continuous with the cell-bodies whose processes they 

 are ; whether or not they are all cell processes is not yet 

 definitely known. 



It will be seen from the above studies that the connec- 

 tive-tissue cells of the cornea are flattened and branched 

 cells, and that certain of them, at least, lie in spaces be- 

 tween the fibres of the intercellular substance. We have 

 now to study more carefully the nature of these spaces ' 

 and their relation to the cells. 



Cornea Treated with Silver Relation of the Cells to the 

 Basement Substance. Strong solutions of nitrate of silver 

 have the power of staining the intercellular substance 

 of connective tissue light brown, while the cells are 

 left uncolored. In order to stain the cornea of the 

 frog with silver, the following process should be em- 

 ployed : The spinal cord of the animal having been broken 

 up with a needle, a finger is introduced into the mouth 

 so as to press the eyeball forward and bring the cornea 

 into prominence ; the membrana nictitans is drawn away 

 with the thumb or a pair of fine forceps, so as to leave 

 the anterior surface of the cornea quite free. The eye 



