CHAP. I. 
AMYLACEOUS TISSUE. 
43 
are expelled from them by an opening at each end of the 
cell, on which account Turpin calls such cells Biforines. 
Morren found the power of emitting their raphides pre- 
served in these bodies after having undergone 6° of cold of 
Reaumur (18° Fahr.), and he therefore concludes that the 
phenomenon is, as Turpin supposes, a mere physical action 
produced by endosmose, and not a vital action. 
(For further remarks on raphides see the Appendix to this 
Work.) 
Sect. VII. Of amylaceous and other granular matter con- 
tained in Tissue. 
Inside the tissue of plants, are found various kinds of 
particles, some of which give colour or its peculiar turbid 
appearance to the fluid, others their nutritive quality to par- 
ticular species. 
Of these some are turned blue by iodine, and are there- 
fore regarded by chemists as composed of amylaceous matter 
or starch; others are rendered olive brown by that agent, and 
many are dissolved by alcohol, whence they are considered of 
the nature of resins : all are decomposed by cold, and appear 
to be connected with the function of nutrition. 
The following kinds may be distinguished : — 
1. Amylaceous granules. — These are so extremely common 
that no plant can be said to be destitute of them, and many 
have the cells of their roots and some parts of their stem 
filled quite full of them. In the rhizoma of Equisetum the 
tubes are so crowded with them, that when the tubes are 
wounded, the granules are discharged with some force, ap- 
parently by the contraction of the membrane, so that they 
appear as if in voluntary motion so long as the emptying the 
tissue continues to take place. These particles are perfectly 
white, semitransparent, generally irregularly oblong, some- 
times compound, and marked with oblique concentric circles ; 
they are extremely variable in size, some being as fine as the 
smallest molecular matter in pollen, that is, not more than g 
