138 Miscellaneous. 
On the Structure of the Anthers in the Aroidez. 
By M. van TIEGHEM. 
From his investigations Chatin has deduced the general rule, that 
anthers which open by terminal pores are destitute of fibrous cells. 
The genus Solanum, the anthers of which have fibrous cells round 
the terminal pore, forms a curious exception to this. The author 
indicates the occurrence of similar exceptions in the apicilar anthers 
of several Aroidee. 
The sessile anther of Richardia africana, Schott, has two loculi, 
each divided into two locelli by a delicate longitudinal septum ; and 
these open at the apex by a small vertical tube pierced through the 
thick plate formed by the connective above the loculi; beneath this 
terminal pore the septum is absorbed, to enable the loculi to com- 
municate. The inner wall of the chamber is clothed, when mature, 
with a layer of prismatic cells perpendicular to its surface, and fur- 
nished with strong spiral bands. In each locellus this layer of 
spiral cells ceases at the two lines of origin of the septum, where it 
curves inwards a little and unites by means of smaller cells with the 
corresponding layer of the neighbouring locellus, thus forming two 
longitudinal ridges. The septum is therefore destitute of fibrous 
cells; when mature, it is composed only of a layer of interlaced 
threads, the remains of the cells of which it was originally composed. 
The delicate cellular membrane which clothes the whole interior of 
the locelli in the young anther is absorbed at the moment of dehis- 
cence. The layer of spiral cells is continued to the terminal pore, 
the inner orifice of which it borders; but it does not line the wall 
of the little tube, which is formed of colourless cells, each con- 
taining a grain of starch, whilst the cells of the plate are larger and 
filled with a yellow liquid. Here, therefore, we have exactly the 
reverse of what occurs in Solanum, where the fibrous cells surround 
the pore without extending upon the inner surface of the cell. 
The mode in which the anther of Richardia emits its pollen shows 
that it is a powerful agent of expulsion. Through each pore a white 
thread is seen to issue and become longer by degrees, which at last 
forms a little cotton-like ball, of a dull white colour, round the ori- 
fice. This filament is composed of two or three parallel rows of 
ovoid pollen-grains united by a gummy liquid; by exposure to the 
air, this cement evaporates, and the grains, becoming free, are dis- 
seminated. The author considers that the contraction of the cell 
causing this expulsion of the pollen is produced by the layer of 
fibrous cells; but he is unable to explain its mode of action. 
In the anther of Alocasia odora and metallica, Schott, each of 
the two cells arranged round the dilated connective is constructed 
nearly in the same manner ; but the cell, instead of opening upon 
the plate itself by a duct traversing its thickness, is bent out- 
wards and opens directly beneath the plate by an orifice common to 
two confluent cells; the fibrous cells predominate round the pore, 
and several other rows are frequently added to the ordinary one at 
the upper part of the curve. 
