a EY sien 
varriitj] THE MECHANISMS OF FLOWERS. 365 
Orv. CAMPANULACE ZZ. 
Tribe Lobeliew. 
Siphocampylus bicolor, G. Don.—The five anthers cohere to form 
a hollow cylinder which becomes filled with pollen, and whose 
anterior opening bends downwards into the mouth of the flower. 
In the first stage the style, with its two stigmatic lobes closely 
applied to one another, extends to the base of the anther-cylinder, 
but gradually grows up through it, brushing the pollen before it 
out of the cylinder by means of a ring of hairs placed behind the 
_ stigmas. When the stigmas issue at the anterior opening of the 
cylinder the two lobes separate and expose their papillar surfaces 
_ to contact with insect-visitors in the upper part of the mouth of 
_ the flower. So insects come in contact in younger flowers with 
_ pollen at the anterior opening of the anther-cylinder, and in older 
_ flowers with the stigmas, and regularly fertilise older flowers with 
_ the pollen of younger (Hildebrand, Nos. 346 and 351). 
Other species of Siphocampylus are believed by Delpino to be 
fertilised by honey-sucking birds (178). 
Isotoma axillaris, R. Br.—The mechanism is for the most part 
similar, but there is a lancet-like appendage to each of the lower 
anthers which extends downwards into the upper part of the 
flower, and which causes shedding of the pollen when touched by 
an insect (Hildebrand, No. 356). 
Lobelia Erinus, L. (2) (Common Blue Lobelia).—The flower, 
" which has been thoroughly described by Mr. T. H. Farrer, agrees 
in all essential points with Siphocampylus bicolor, and is visited by 
_ bees (240). | 
Delpino saw Lobelia Erinus visited by Halictus (178). Hilde- 
brand observed in the same species that the style is frequently not 
able to force its way through the closed end of the anther-tube, 
and that in such a case the stigmatic lobes unfold within the 
anther-tube and are self-fertilised (360). | 
Lobelia syphilitica, L., is abundantly visited by Bombus ttalicus 
and B. terrestris (Delpino, 172, 176). 
Lobelia fulgens, Willd.—Delpino suggested that this plant is 
fertilised by humming-birds (172, 176), and Trelease afterwards saw 
the flowers visited by the Ruby-throated Humming-bird (727, 751). 
Heterotoma ditfers from Siphocampylus in having all the lobes of 
the corolla bent«downwards, in the lower portion of the corolla: being 
