542 
PHANEROGAMS, 
But, besides, the morphological homology of the separate parts of the ordinary 
stamens is not yet altogether determined, more precise investigations into the history 
of development being still wanting in this direction. Cassini and Roper consider 
the two anther-lobes as the swollen lateral halves of the lamina of the stamen ; their 
loculi would therefore in that case be mere excavations in the tissue of the leaf; 
the pollen-mother-cells become differentiated inside the young tissue of the leaf, 
According to this view the furrow between the two pollen-sacs of an anther-lobe (see 
Fig. 357, H) would correspond to the margin of the staminal leaf; but this cannot be 
the case\ at least not always, according to Mohl's observations. When the stamens 
become transformed into petals (by the so-called 'doubling' of the flower) as in the 
Rose, Poppy, Nigella da??iascena, &c., it may be observed with certainty that the 
anterior and posterior loculi do not stand opposite one another, which would be 
the case if one belonged to the upper, the other to the under side of the staminal 
leaf ; but that both are formed on the upper surface, the anterior ioculus nearer the 
median line of the leaf, the posterior one nearer its margin. It is further observable 
that in such cases the two pollen-sacs of an anther-lobe do not always stand close to 
one another, but that they are frequently separated by a tolerably broad piece of the 
leaf, and that this intermediate piece contracts in the normal state into the par- 
tition-wall between the two pollen-sacs. The greater stress must be laid on these 
observations of Mohl, because in them the abnormal development only shows more 
plainly what can often enough be seen in a horizontal section of the anther and 
connective of normal stamens, viz. that the pollen-sacs of an anther-lobe evidently 
belong to one side of the stamen ; it appears, however, that they must in some cases 
be referred to the under (Fig. 357, C, H), in others to the upper side (Fig. 360, C). 
The origin of the pollen-mother-celis and the development of the wall of the separate 
pollen-sacs calls to mind so vividly in all essential features the corresponding pheno- 
mena in the sporangium of Lycopodiacese and even of Equisetacese, that it may be 
und Gnetaceen, 1872. — Hieronymus, Zur Deutung sogen, axiler Antheren, Bot. Zeit. 1872, and 
Beitr. z. Kennt, d. Centrolepidaceen, Halle 1873. — Reuther, Beitr. z. Entwick. d. Blüthe, Bot. Zeitg. 
1876. — Engler, Beitr. z. Kennt, der Antherenbildung, Jahrb. f. wiss. Bot. X. 1876. — Celakovsky, 
Teratologische Beiträge zur morphol, Deutung des Staubgefä ses, Jahrb. f. wiss. Bot. XI. 1878. 
With reference to Typha, Magnus finds that the apparently axial stamen consists really of three 
coherent lateral stamens. In Naias, Casrmrina and Cyclanthera, the stamen is undoubtedly axial. 
It would appear, therefore, that stamens are not always phyllomes. It is still possible, however, that 
they may be phyllomes in these cases. Celakovsky goes so far as to regard the stamen of Naias as 
a terminal leaf, a quite impossible morphological conception (Flora, 1874). The researches of 
Hieronymus tend to show that the statement made above on p. 491 may be near the truth, namely, 
that in these cases the pollen-sacs may be the surviving portions of otherwise abortive staminal leaves. 
In Brizula, one of the Centrolepidacese, he finds a single axial stamen ; in Alepyriivi and Centrolepii he 
finds that the stamen is developed from one longitudinal half of the growing-point, and that the other 
half, the persistent growing-point, is forced on one side by the growth of the stamen, so that the 
stamen lies in the same straight line as the long axis of the stem. He finds this to be the case also 
in a Grass, Festnca psetido-mynrus ; in the nearly-allied F. geniculata, which usually has three lateral 
stamens it sometimes happens that only one stamen is present, and this is then developed in the 
manner described above. On the other hand, these facts may be used to prove that a stamen may be 
sometimes a caulome and sometimes a phyllome. It must be borne in mind that the ideas of 
caulome and ph}llome are relative and not absolute.'] 
^ H. V. Mohl, Vermischte Schiiften, p. 42. 
