now TO DISSECT A FLOWER. 
147 
The lower portion of the ovaries when viewed under the micro- 
scope is seen to be thinly covered with delicate transparent hairs. 
Of course the ovaries are superior. 
It needs no botanical knowledge or experience to detect many 
and important differences between the structure of the flower of 
thefigwort and that of the primrose. Difl*erence in the calyx, differ- 
ence in the corolla, in the structure and position of the stamens, in 
the pistils, in the ovaries ; in fact, in almost every particular, 
except that the ovaries are superior in both. In comparison 
with our last example, or indeed with any buttercup, we would 
recommend the student to seize the opportunity in the autumn 
of dissecting the flower of the common bramble, and carefully 
compare notes on the structure of the flowers of buttercups 
and brambles, as well as the mature fruit of both. Such an 
examination cannot fail to impart silent instruction. 
The sweet violet ( Viola odorata) has a flower differing so 
much from the preceding, that a brief sketch of its dissection is 
desirable. A first glance will detect both calyx and corolla, the 
former consisting of five equal green sepals, and the latter of 
five petals, of which four are nearly equal, and the fifth or lower 
one unequal. If the Tour upper petals are removed one by one, 
the form of the fifth will be better seen. It is not easy to re- 
move the fifth petal entire (fig. 22), for a reason which will be 
hereafter apparent. This unequal petal is produced backwards 
into a kind of pouch or spur, passing between and beyond two 
of the sepals of the calyx, which are thereby extended. If a 
section of a complete flower (fig. 21) is made with a sharp 
knife from the base outwards, passing through the centre of the 
spur, the whole structure may be viewed with a pocket lens. The 
sepals are attached, not at the extreme base, but a little above 
it, and the low^er petal forming a kind of bag or pouch, into 
which a horn or spur protrudes from the centre of the flower. 
Each sepal and each petal being unconnected to its neighbour, 
the violet is therefore polysepalous and polypetalous, but it 
must not be forgotten that the corolla is irregular. 
The stamens will be observed to stand so close together that 
they touch each other, and form a kind of tube around the 
ovary (fig. 25). A dissecting needle or the point of a knife 
will remove them one by one, and as thus removed, they should 
be placed side by side upon the table at which the operator is 
seated. Five stamens, and all with very short filaments — or 
rather, apparently so, for the filaments pass along the back of 
the anthers, and are continued above them in a sort of trian- 
gular crest (fig. 23). All the stamens are thus created, and 
three are alike ; but two others of the five have a spur which is 
prolonged backwards (fig. 24), and enters the pouch of the lower 
petal. The stamens, therefore, are irregular, two of them being 
