44 
ORGANOGRAPHY. 
BOOK I. 
of an inch in diameter, others being as much as yoVo f Jo* 
They often form the centre of the grains of chlorophyll, as 
Mohl has shown. In the milky juice of Euphorbia, they 
assume the singular appearance represented at Plate II. fig. 19. 
Z>., looking like short cylinders enlarged at each end into a 
round head : double-headed granules of this kind are not as 
yet found elsewhere ; Morren states that they vary in form in 
different species of Euphorbia. 
Their nature has been carefully investigated by Fritzsche 
(Ueber das Amylum^ Berlin, 1834, and Poggendorf's Annalen, 
1834, No. 9, 10.), who has proved them to be formed by the 
successive deposit of new layers, one over the other, and not 
to be cells containing soluble matter, as Raspail asserts. 
Those which have the smallest size have a distinct motion 
of rotation when suspended in water ; and this motion looks 
as if spontaneous ; for of several floating near each other, in 
the same medium, a part will be in active motion, while 
others remain inactive. 
Turpin calls these granules GlobuUne, and considers them 
the most elementary conditions of vegetable tissue, its primitive 
form ; an opinion which is adopted, with some modifications, by 
Raspail, who looks upon each granule as one of the element- 
ary molecules of tissue in a state of development. This 
writer assigns them a point of attachment or hilum, by which 
they originally adhered to the parent cell : he considers that 
cellular tissue is produced by the development and mutual 
pressure of each granule, and that all the varied forms of 
plants may be explained by reference to this principle. 
(Nouv. Sgst de Chimie Organique, p. 83.) Morren states that 
these grains of fecula are the first stage of a crowd of organs, 
and that he can demonstrate the free spiral thread of Collomia 
and Salvia to be at first an amylaceous granvde. This, how- 
ever, does not correspond with the statements of Schleiden. 
Such amylaceous granules appear to have, under particular 
circumstances, the power of spontaneous growth, by which they 
multiply and increase themselves externally. This is parti- 
cularly visible in the fecula of Barley ; which, if observed in 
its original state, is found to be composed of angular, irregular 
bodies, some of which are of extreme minuteness, and seem 
