. Physiological botany; I. Outlines of the histology of phænogamous plants. II. Vegetable physiology. Plant physiology; Plant anatomy. 48 THE VEGETABLE'CELL IN starch, or with great regular- ity, as in wlieat. This point is known as the nucleus, or hilum. If two or more nuclei are dis- cernible, the granule is said to be compound. 23 Occasionally manj' small sin- gle granules cohere slightly to form an aggregate which can be easily- broken. According to Wiesner, there may be as many as 30,000 granules in a single aggregate of this kind. Both simple and compound granules may occur in
. Physiological botany; I. Outlines of the histology of phænogamous plants. II. Vegetable physiology. Plant physiology; Plant anatomy. 48 THE VEGETABLE'CELL IN starch, or with great regular- ity, as in wlieat. This point is known as the nucleus, or hilum. If two or more nuclei are dis- cernible, the granule is said to be compound. 23 Occasionally manj' small sin- gle granules cohere slightly to form an aggregate which can be easily- broken. According to Wiesner, there may be as many as 30,000 granules in a single aggregate of this kind. Both simple and compound granules may occur in the same cell, but some plants have only simple, and others only com- pound granules. Canna and Curcuma may be cited as exam- 'S^J^^kf^.iSMt^i ~C^ pies of the former; Jatropha, of ^ *V;*i«^^ li the latter. Since starch occurs in every plant in all stages of development, the size of the granules must be extremely variable. Nevertheless, a statement of the more common limits may aid in their identification. Wiesner gives the following limits of size for some of the more common sorts of starch, first grouping them into small, medium, and large grannies. Small granules (from to mm.) : as the simple granules of rice, oats, buck- wheat ; also the smaller granules of wheat, rye, barley, etc. Medium granules (from to mm.) : as the compound granules of rice and oats, the larger ones of wheat, rye, and barley, the simple granules of Indian corn, and of the common leguminous plants. Large granules (distinguishable as granules to the naked eye) : as the simple granules of Curcuma leucorrhiza, Canna edulis, potato, etc. Fig. 23. Starch-granules from the bnlb of Phajus grandifoliiis, showing the nu- cleus at the upper part and the starch generator or amylogcnic body below, 'f. (Scliiuiper.) Fro. 24. Cells from potato-tuber, showing starch-granules (Schmidt) Fio. 25. Starch-granules from sarsapariUa. (Berg and Schmidt.). Please note that these images are extracted from
Size: 1659px × 1506px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectplantanatomy, bookyea
