This secreting portion is, strictly speaking, the true stigma, but the name is generally applied to all the divisions of the style on which the stigmatic apparatus is situated.
In the British genera and many others they are numerous, forming a whorl round the top of the axis in the centre of the flower, the united styles rising from the centre and bearing a corresponding number of stigmatic branches.
On the skin are several scattered, circular, very minute spinnerets; the stigmatic spines are long and conspicuous, and along the edge runs a row of conical hairs or spines.
It is closely wrapped in the cast skin of the secondary larva, a skin consisting of a diaphanous bag, without any outlet, with running along each side a white tracheal thread which connects the various stigmatic apertures.
Each side has a white edging of shrivelled tracheæ, running from one stigmatic orifice to another.
On this second sac are found the stigmatic warts, the thoracic studs and so forth, which we noted on the pseudochrysalis.
The stigmaticapertures have a projecting, dark-red rim.
Later, the lower portion of the style-branches, that is covered with stigmatic papillae along the edge, emerges from the tube to receive pollen carried from younger flowers when the visitor sips his reward.
Now the released keel curves all the more, and splits open to release the stigmatic tip of the style that touches any pollen the bee may have brought from another blossom.
Presently he backs out, brushes the pollen from his head and thorax into his baskets, and is off to fertilize an older, stigmatic flower with the few grains of quickening dust that must remain on his velvety head.
But when the anthers have shed their pollen, and the filaments have spread outward and away from the pistil, the three stigmatic arms branch out to receive the fertilizing dust carried from younger flowers by their busy friends.
Flies which feed on the pink's pollen only, sometimes come by mistake to older blossoms in the stigmatic stage, and doubtless cross-fertilize them once in a while.
Styles thread-like, stigmatic down the inner side, persistent.
Stamens monadelphous, the anthers permanently attached to a large stigmatic body; pollen mostly in waxy masses.
Ovary with a single cell and ovule, tipped with a long laterally stigmatic style, maturing as an achene.
Style elongated awl-shaped, stigmatic and papillose down one side.
Stigmas sessile, awl-shaped or slender, spreading or recurved above, persistent, stigmatic down the inner side.
Styles 2--8, united below, or distinct, stigmaticalong the inside.
Ovaries 2, tapering into very short styles; the large depressed 5-angled fleshy stigmatic disk common to the two.
Style long and thread-shaped, stigmatic down one side.
Style single, thread-shaped, stigmaticdown one side, received in the groove between the lobes of the large anther.
Muller has described the stigmas of all three forms with great care, and he appears to have found the stigmatic papillae differing constantly in length and structure in the three forms, being longest in the long-styled form.
In the long- styled form alone the stigmatic surfaces of the mature pistils twist round, so as to face the circumference of the flower; but to this point I shall presently return.
The stigmatic hairs or papillae on the former are .
The length of the pistil in the long-styled form of Linum grandiflorum varies much, and the stigmatic papillae vary in a corresponding manner.
Repeated the experiment, with the same result after twenty-four hours, excepting that only two own-form grains had penetrated the stigmatic tissue with their tubes to a very short depth.
Muller gives figures of the stigmatic papillae of the two forms, and those of the long-styled are seen to be more than double the length, and much thicker than the papillae of the short-styled form.
I could detect no difference in the two forms in the size of the stigmatic papillae.
Owing to the state of the specimens, I could not decide whether the stigmatic papillae were longer in the one form than in the other.
After an interval of eighteen hours, the tubes penetrated the stigmatic tissue, but to what depth I did not ascertain.
The two forms of the male differ in their pistils: in some plants it is quite small, without any distinct stigma; in others the pistil is much more developed, with the papillae on the stigmatic surfaces moderately large.
There is only a single fertile stamen; the style is almost obsolete, with the three stigmatic surfaces directed to one side.
It has also been observed that when pollen of one species is placed on the stigma of a distantly allied species, though the pollen-tubes protrude, they do not penetrate the stigmatic surface.
On the other hand, I have found by experiment that the fertility of clover depends on bees visiting and moving parts of the corolla, so as to push the pollen on to the stigmatic surface.
How strange that the pollen and stigmatic surface of the same flower, though placed so close together, as if for the very purpose of self-fertilisation, should in so many cases be mutually useless to each other!
As this process much more resembled the vesicles that preceded the stigmatic bleedings, it was examined with greater care.
Bolbophyllum is remarkable for the closure of the stigmatic cavity which comes on after the flower has been open a little while, instead of after fertilisation, as in other genera.
I will say nothing about the rostellum, stigmatic utriculi, fertility of Acropera and Catasetum, for I am completely bewildered: it will rest with you to settle these points by your excellent observations and experiments.
I should think the non-viscidity of the stigmatichollow was due to the plant not living under its natural conditions.
I fully admit the difficulty of similarity of stigmatic chamber in the two Acroperas.
How strange that the pollen and stigmatic surface of the same flower, though placed so close together, as if for the very purpose of self-fertilisation, should be in so many cases mutually useless to each other!
It has also been observed that when the pollen of one species is placed on the stigma of a distantly allied species, though the pollen-tubes protrude, they do not penetrate the stigmatic surface.
Each flower tends to have two yellowish green stigmatic lobes but three-lobed stigmas may be found and one case of a 4-lobed stigma was observed.
Most female flowers of shagbark have 2 stigmatic lobes, however, 3 stigmatic lobes resulting in triangular nuts are not uncommon.
Pleural elements are developed in the form of narrow stigmatic plates, with the free edge directed backwards.
Even the production of a fine and seemingly mature fruit is not a certain indication of good seeds, for seed capsules have been produced by irritation of the stigmatic surface by grit or dust, but no fertile seeds can be thus produced.
This is readily accomplished by lifting the pollen masses beneath the anther-cap with a thin pencil or sharpened stick and placing them on the stigmatic surface of the seed-bearing parent.
The column has a prominent staminode with two fertile anthers below it, one on each side of the column and behind the stigmatic plate.
The stigmatic secretion acts on the pollen of a plant of the same species in a wholly different manner to what it does on the pollen of one belonging to a distinct genus or family.
At this time the inner or stigmatic surfaces of the pistils will be exposed and ready for the pollen.
The iris flower is of special interest as an example of the relation between the shape of the flower and the position of the pollen-receiving and stigmatic surfaces on the one hand and the visits of insects on the other.
The upper part of the style now divides into two parts, and the branches diverge, exposing the stigmatic surfaces which form the inner sides of the fork.
In this position, however, they would be useless, as they would miss the stigmatic surface of the next flower visited by the moth.
So intensely susceptible is the stigmatic surface of the Cypriped that a touch excites it furiously.
In the latter position, if the insect visited another flower, the pollinium would exactly hit the sticky stigmatic surface and thus effect fertilisation.
The long-styled flowers have a spherical stigma provided with large stigmatic papillae; the pollen grains are oblong and smaller than those of the short-styled flowers.
