424* PROF. OLIVER ON THE STRUCTURE OF THE ANTHER. 
that the anther results from a metamorphosis of the lamina of the leaf*. Prom the 
examination of a transverse section of the form of anther generally prevailing in flower- 
ing plants, in its young state and prior to the absorption of the vertical septa which pass 
from the connective through each lobe, thus rendering it four-celled, it may reasonably 
be supposed that the margins of these septa, answering to the longitudinal sutures and 
lines of dehiscence of the anther, correspond likewise with the margins of the lamina of 
the stamen-leaf — the septa, however, being plates of untransformed tissue of uncertain 
homology. The opinion that the sutures of the anther correspond to the margins of the 
leaf, and that the pollen- cavities, separated by the septa of unchanged tissue, originate 
in its parenchyma, was advanced, according to Von Mohl, by Cassinif ; and the same view 
has been maintained by Roeper|, Schlechtendal§, Grisebach, and others. Among 
botanists holding this opinion, who have recently expressed themselves definitely upon 
the subject, I find Prof. Grisebach, in his "Grundriss d. syst. Botanik"||, says, "The 
layers of the anther in which the pollen is formed answer to the four parenchym-layers 
of a leaf, in which the midrib and the vascular bundles correspond, in respect to their 
situation, to the parenchymatous septa in the anther between the pollen-originating 
layers." Dr. Asa Gray, in his « Introduction to Botany ' (1858)^", says, " A transverse 
section of the forming anther shows four places in which the transformation of the 
parenchyma into pollen commences, which answer to the centre of the four divisions of 
the parenchyma of a leaf,— viz., the two sides of the blade, distinguished into its upper 
and lower stratum. So that the anther is primarily and typically four-celled,— each lobe 
being divided by a portion of untransformed tissue, stretching from the connective to the 
opposite side, which corresponds to the margin of the leaf and the line of dehiscence." 
And further, " Viewed morphologically, therefore, the filament answers to the petiole of 
a leaf, the anther to the blade ; the connective represents the midrib, the lobes or cells of 
the anther represent the two symmetrical halves of the blade, and the line of dehiscence 
is normally along the margins of the transformed leaf." Dr. Lindley, in ' Introduction 
to Botany**,' says, "The line of dehiscence in ordinary circumstances is the margin of 
the modified leaf." Neumann, in the paper before referred to, upon anticous and pos- 
ticus anthers, expresses the opinion very decidedly that the anterior and posterior 
cells of each anther-lobe correspond to opposed strata of the metamorphosed leaf, and 
that the suture answers to its margin. Somewhat different from the foregoing is the 
theory of Bischoff ft. He maintained that the suture of the anther does not correspond 
to the leaf-margin ; that the loculaments develope upon its superior surface, within the 
ays, referring to these monstrous stamens, " Cependant ces antheres, n'ont pas en general la 
* He 
structure anatomique propre a ce systeme d'organes. Ainsi le plus souyent les renflements ne presented pas des 
points ou la couche fibreuse interrompue pourrait permettre la libre sortie dn pollen. Cependant on voit dans la 
hgure que la couche fibreuse tres-amincie en a [this refers to a cross-section of one of the anthers, showing a 
Somewhat similar abnormal 
f Opus. Phytol.ii. p. 551. 
§ LinnEea, i. (1826), o. 6 
lobes] 
ured by Kaspail (Mem. Soc. d'Hist. Nat. Paris, iii. tab. 2, 45-6) 
t 
lamuea, i. ( 1826), p. 602. In « Obs. on Monstrosity of a Garden-Tulip." 
II (1854), p. 40. P 
