248 ATTACHMENT OF THE FILAMENT TO THE ANTHER. 
readily see that the two lobes of the anther correspond to the 
two halves of the lamina folded upon themselves ; in fact, if we 
take the blade of a leaf and fold it in the above manner, and then 
make a transverse section, it will present a great resemblance to 
the section of the anther already described (fig. 513). We may 
therefore conclude: that the anther corresponds generally to the 
lamina of the leaf, the connective to the midrib, the outer surface 
to the epidermis of its lower side, and the septa to the epidermis 
of the two halves of the upper surface of the lamina united and 
considerably thickened. The pollen corresponds to the paren- 
chyma situated between the epidermis of the upper and lower 
surfaces of the lamina of the leaf. 
Rig o22. Fig.d2a. 
Fig. 522, A portion of the flower of the White Water-lily (Nympheea alba), 
consisting of a gyncecium invested by a large fleshy disk which is pro- 
longed fromthethalamus. The pistil is surrounded by some stamens which 
have petaloid filaments and adnate introrse anthers; and by two petals. 
Fig. 523. Gyncecium and andreecium of the Tulip. The stamens eé 
and ce have introrse anthers, which dehisce longitudinally. 
Attachment of the Filament to the Anther.—The mode in which 
the anther is attached to the filament varies in different plants, 
but it is always constant in the same individual, and frequently 
throughout entire natural orders, and hence the characters 
afforded by such differences are important in practical botany. 
There are three modes of attachment which are distinguished 
by special names. Thus: Ist, the anther is said to be adnate or 
dorsifixed when its back is attached throughout its whole length 
to the filament, or to its continuation called the connective, as 
in the Magnolia (fig. 526), and Water-lily (fig. 522); 2nd, it 
is innate or basifixed when the filament is only attached to its 
base, and firmly adherent, as in the species of Carex (fig. 503) ; 
and 3rd, it is versatile, when the filament is only attached by a 
point to about the middle of the back of the connective, so that 
the anther swings upon it, as in Grasses generally (fig. 505), 
and in the Lily, Evening Primrose, and Meadow Saffron. 
Connective.—The relations of the anther to the filament, as 
well as its lobes to each other, are much influenced by the ap- 
