8 ORGANOGRAPHY. BOOK I. 



colourless. Examine the red bladder, and you will find it 

 filled with a colouring matter of which the rest are destitute. 

 The bright satiny appearance of many richly coloured flowers 

 depends upon the colourless quality of the tissue. Thus, in 

 Thysanotus fascicularis, the flowers of which are of a deep 

 bi-illiant violet, with a remarkable satiny lustre, that appear- 

 ance will be found to arise from each particular cell containing 

 a single di'op of coloured fluid, which gleams through the 

 white shining membrane of the tissue, and produces the flick- 

 ering lustre that is perceived. Colouring matter of the cellular 

 tissue is frequently fluid, but is in the leaves and other parts 

 more commonly composed of granules of various sizes : this is 

 particularly the case in all green parts ; in which the granules 

 lie amongst greenish liquid, the latter of which, as the cells 

 grow older, dries up, while the granules themselves gradually 

 change to olive green, and finally to brown. 



Kieser distinguishes three sorts of globules among tissue : 

 — 1. Round extremely transparent bodies, of a more or less 

 regular figure, found principally in young plants and in coty- 

 ledons, and soluble in boiling water ; it is these that constitute 

 starch or faecula. 2. Globules of a small size, a more irre- 

 gular figure, and coloured either gi'een or some other tint. 

 They are not soluble in water, but are so in alcohol ; but 

 when dissolved, their matter is not precipitated by the addition 

 of water, on which account they are distinguishable from 

 resinous substances. 3. Extremely small round bodies, vary- 

 ing in colour, and found floating in the proper juices of 

 vegetables. 



The fix'st mentioned granules are v/hat Turpin calls Globu- 

 line. He believes them to be young cellules, and that it is 

 from them that new tissue is developed. Tliere does not, 

 however, appear to be any sufficient evidence of this, which 

 must be considered at present mere hypothesis. It has, how- 

 ever, been substantially adopted by Raspail, who asserts that 

 each such granule has a point of attachment, by which it ad- 

 lieres to the lining of its mother cell ; that it is by the 

 developement of such granules and their mutual pressure that 

 cellular tissue is produced; and that all the varied forms 

 assumed by the organs of p'ants may be explained by refer- 



