338 DR. E. DE FRAINE ON THE 
of aerenchyma in the parts named. The tissue consists of very thin walled 
parenchymatous cells, with cellulose walls; the cells, which are generally 
longer than they are broad, are arranged in irregular rows. In transverse 
Fra. 10. 
Transverse section of the aerenchyma of S, herbacea, Linn. x 290. 
Ев. 11. 
Radial longitudinal section of the aerenchyma of S. herbacea, Linn. х 290. 
section the cells, which are drawn out at either end, thus diminishing the 
contact area, appear to be covered with large pores (text-fig. 10). Radial 
sections through the tissue show that the irregular rows are connected with 
one another by means of tubular outgrowths, one or more arising from each 
