Ancient Plants / Being a Simple Account of the past Vegetation of the Earth and of the Recent Important Discoveries Made in This Realm of Nature

by Marie Carmichael Stopes

Fig. 32

Bast.—Sieve tubes, long cells which carry foodstuffs, cross walls pitted like sieves, s, [fig. 32]. In transverse section in [fig. 33].

Companion cells, narrow cells with rich proteid contents, c, [fig. 32]. In transverse section at c, [fig. 33].

Bast parenchyma.—Soft unspecialized cells mixed with the sieve tubes, p, [fig. 32].

Bast fibres.—Thick-walled sclerenchymatous cells mixed with, or outside, the soft bast.

Fig. 33

Cambium.—Narrow cells, like those of the cork cambium, which lie between the wood and bast, and give rise to new tissues of each kind, cb, [fig. 33]. Compare [fig. 114], fossil.

There are, of course, many minor varieties of cells, but these illustrate all the main types.