18431862] INSECT FERTILISATION 259 



insect, presses " against the slightly projecting lower lip of the indusium, Letter 590 



opens it, and some of the hairs enter and become smeared with pollen." 



The yield of pollen is therefore differently arranged in Leschenaultia ; 



for in the more typical genera it depends on the growth of the style 



inside the indusium. Delpino, however (see Hildebrand's version, loc. 



<rzV.), describes a similar opening of the cup produced by pressure on the 



hairs in some genera of the order. 



Down, June 7th [1860]. 



Best and most beloved of men, I supplicate and entreat 

 you to observe one point for me. Remember that the 

 Goodeniaceae have weighed like an incubus for years on my 

 soul. It relates to Sccevola microcarpa. I find that in bud 

 the indusium collects all the pollen splendidly, but, differently 

 from Leschenaultia, cannot be afterwards easily opened. 

 Further, I find that at an early stage, when the flower first 

 opens, a boat-shaped stigma lies at the bottom of the 

 indusium, and further that this stigma, after the flower has 

 some time expanded, grows very rapidly, when the plant is 

 kept hot, and pushes out of the indusium a mass of pollen ; 

 and at same time two horns project at the corners of the 

 indusium. Now the appearance of these horns makes me 

 suppose that these are the stigmatic surfaces. Will you look 

 to this ? for if they be by the relative position of the parts 

 (with indusium and stigma bent at right angles to style) [I 

 am led to think] that an insect entering a flower could not 

 fail to have [its] whole back (at the period when, as I have 

 seen, a whole mass of pollen is pushed out) covered with 

 pollen, which would almost certainly get rubbed on the tw r o 

 horns. Indeed, I doubt whether, without this aid, pollen 

 would get on to the horns. What interests me in the case is 

 the analogy in result with the Lobelia^ but by very different 

 means. In Lobelia the stigma, before it is mature, pushes by 

 its circular brush of hairs the pollen out of the conjoined 

 anthers ; here the indusium collects pollen, and then the 

 growth of the stigma pushes it out. In the course of about 



going to suck the nectar, the straggling hairs of the brush opened the lip 

 of the indusium, entered it, stirred up the pollen, and brought out some 

 grains. I did this to five flowers, and marked them. These five flowers 

 all set pods ; whereas only two other pods set on the whole plant, though 

 covered with innumerable flowers. . . . I wrote to Mr. James Drummond, 

 at Swan River in Australia, . . . and he soon wrote to me that he had 

 seen a bee cleverly opening the indusium and extracting pollen." 



