66 COLLENCnYMA CELLS 



2. De Baiy, pp. ll'J-12U. 



3. Eames and ^lacUaiiiels, pp. 54-56. 



4. Esau, K., Ontogeny and Structure of Collenchyma and of 

 Vascular Tissues in Celery Petioles. Ililgardia 10:431-467. 

 1936. 



5. Ilaberlandt. i^p. 155-158. 



6. Hay ward, p. 22. 



