CHAP. I. 
CELLULAR TISSUE. 
15 
resemblance to the teeth of a currycomb, in the anthers of 
Campanula; first noticed by Purkinje. (Plate I. fig. 18.) 
13. Fibres forming distinct arches, as seen in the anthers of 
Linaria cymbalaria, &c. by Purkinje. (Plate I. fig. 4.)* 
Vasiform Cellular Tissue {Tubes poreux^ Vaisseaux en 
cliapelet, M.\Yhe\\ Tubes corpuscuUferes of Dutrochet.) Tissue 
of this kind consists of tubes whose sides are marked with nu- 
merous dots, arranged in a more or less spiral manner, and 
which are divided internally by transverse partitions. Usually, 
in addition to the dots, there is distinctly visible an oblique or 
annular transparent line upon the walls of the tube. (Plate II. 
fig. 15.17.) Hence Kieser viewed them as spiral vessels, the spires 
of which, when old, elongate, and become connected by a dotted 
membrane. BischofF, on the contrary, considers the dots to 
be caused by the separation of a spiral fibre into extremely 
minute portions; and he gives a figure (Plate II. fig. 16.) of 
the manner in which he considers this change to occur. 
It is certain, however, that this kind of tissue, which has 
been called the dotted duct, is really a modification of cellular 
rather than of vascular tissue, as was long since asserted by 
Du Petit Thouars {A7in. des Sciences, vol. xxi. p. 224.); for 
the following reasons : — If it were such a modification of the 
spiral vessel as Kieser supposes, it would have none of those 
internal partitions by which it is particularly known. The 
same remark applies to the theory of Bischoff, which is also 
imperfect, in not accounting for the nature of the transverse 
transparent lines that mark the sides of the so-called dotted 
ducts. Besides, this tissue always terminates abruptly, not in 
acute cones, as has been seen by myself, and as was first well 
represented by Griffith, in his excellent illustrations of the 
anatomy of Phytocrene (Plate II. fig. 19, 20.), and it 
readily separates at the partitions ; none of which properties 
* According to the last mentioned author, the fibres themselves are 
generally tubular, and either perfectly round or somewhat compressed, or 
even three or four sided. He considers it proved that they are hollow, by 
their appearance when compressed, by their occasionally containing bub- 
bles of air, and by the difference between their state when dried and when 
recent. 
