TISSUE FORMATION. 



61 



FIG. 14. Various forms of cells : a. Conical, b. Oval. c. Prismatic, d. Cylindric. 

 -_ Sinuous, f. Branched, g. Entangled, h. Stellate, z. Fibro-cellular tissue. 



FlG. 15. Annular, dotted, and spiral vessels and ducts. 



tissue occur among a mass of cellular tissue; but in 

 Exogens, as the maple, oak, etc., we' find a more reg- 

 ular arrangement of pith, medullary sheath, wood, bark, 

 6 



