By ALEX. G. HAMILTON. 209 



Tiie indusium is bilabiate in Brunoaia, as in SeUiera (Figs. 14 

 and IS), the outside of the style is glandular and has gland-tipped 

 hitii-s all round for half its length upwards, and a few stiff hairs 

 grow on the outside of the indusium. The stigma grows out 

 transversely to the mouth (Fig. 20), in which it differs from all 

 other plants of the order which I have examined. 



The conclusion I have ariived at with regard to the first four 

 plants is, that the contrivances all point to cross-fertilisation by 

 insects, but that in case of that failing, the same contrivances 

 secure fertilisation by the plant's own pollen. 



It is interesting to compare the methods of distributing the 

 pollen in the three natural orders, Lobeliacece, Goodeniacece, and 

 Cam^ianulacece. In the first, the antlieis surround the style 

 closely, and as that organ grows upwards, it pushes the pollen 

 before it, so that it issues in a stream from the orifice of the tube 

 formed by the anthers. In the second order, the open indusium, 

 pushed up Vjetween the anthers by the growth of the style, brushes 

 the pollen into itself, and then closing, the outgrowth of the 

 enclosed stigma forces the pollen out gradually. In the last, the 

 anthers are closely adpressed to the style, and wither, leaving their 

 pollen adhering to it in a uniformly thick coat; the pollen is then 

 set free by the drying up of the sticky glands on the style, to 

 which it adhered, and is carried off by insects which visit the 

 flower in search of nectar and pollen. These very different 

 methods of securing the same end are all the result of modifica- 

 tions of the .same organs. 



I am inclined to think that the study of this subject throws 

 some light on the descent of the order Goodeniacece. I take 

 Sccevola to be the ancestral form, or the neai'est to it, on account of 

 its manifestly simpler arrangements for fertilisation ; and this view 

 I think supported by the fact that Sccevola is the only genus of 

 the order which is very widely distributed, being found in Aus- 

 tralia, New Zealand, several Pacific islands, Asia, Africa, South 

 America, and the West Indies. 



