INTERNAL STRUCTURE OF PLANTS. 
19 
fig. 2, which, however, in the final papilla, seems to be bound 
into a sac. This papilla disappears when the leaf begins to 
grow. The projection of the trunk itself, with the young 
leaves or the bud, is found in fig. 4, magnified 100 times ; and 
in fig. 3, magnified 180 times. There is scarcely any foreign 
matter perceptible in the leaves, but a granule is certainly 
found in the projection of the trunk, which afterwards dis- 
appears ; no trace of cells is, however, found any where one 
within another. If we were to call the entire young leaf a 
mother cell, in as much as it may be surrounded by a cuticle, 
this would be a mere quibble, since this little skin is torn and 
disappears, and thus allows the cells to come forward ; indeed, 
the individual cell distinguishes itself from the skin of the 
leaf, by the former enclosing no other cells than that of the 
latter. Fig. 5 exhibits a young bud of Quercus rohur. It 
exhibits just the same structure as the juicy plants, a pro- 
jection of the branch furnished with leaves, the only difference 
being this, that it is curved in this and straight in that. 
Cells, 780 times enlarged from the projection, are seen in 
fig. 6. The green substance, chlorophyll, is exhibited dis- 
tinctly, of a pale green colour ; but one cell within another is 
nowhere to be seen. All this is confirmed by the represen- 
tation of a bud of Syringa vulgaris, which would only have 
developed itself in the following year. As young cells are 
never perceived, therefore, in the interior of the old cells, we 
have reason to assert, that an enlargement of the cellular 
tissue, by means of mother cells, does not take place in these 
plants. 
A preliminary answer to H. Mold’s treatise, respecting the 
structure of the annular ducts, by Dr. M. J. Schleiden, is 
found in Flora, vol. xxiii. p. 1. It is necessary, however, to go 
back as far as the year 1839 ; partly in order to understand 
the subject in general, and partly because Meyen’s represen- 
tations are very defective. The same author has published ob- 
servations in the same journal, respecting spiral formations 
in the cells of plants. The cells of plants, he states, inclusive 
of the so termed vessels — but setting aside the latex ducts — 
exhibit two periods in their life. In the first period, which 
411 
