

. 137 



perfection only when, being easily discernible by them, it is as little 

 attractive as possible to other insects. The color and odor of the 

 flowers of^ ScropJmlaria, and the quality of their nectar evidently 

 tend to this end. The same observer, watching a wasp on S. nodosa^ 

 found that the first flower on the stem which it visited was the top 

 one ; from this it passed to the others in a somewhat irregular man- 

 ner going downwards, and finally left the plant from the lowest 

 flower (/. c, p. 565). This procedure was said to bring the insect 

 first to the youngei, pistillate flowers ; then to the older, staminate 

 ones. My own studies show a very great irregularity in the visits of 

 wasps, but this irregularity is largely conducive to cross-fertilization 

 in its widest sense. So far as I know, the insects which visit the 

 flowers for polkn go only to those whose anthers are dehiscent, and 

 can have little influence in effecting pollination, except incases where 

 the stigma is still unfertilized when the stamens begin to mature. 



So far as may be judged from reliable statements, and from per- 

 sonal observation, Scrophularia is therefore perfectly adapted to 

 cross-fertilization by the aid of insects, and the favored visitors are 

 wasps. ^ Sprengel could not believe that if, as Kolreuter and Medi- 

 cus insisted, fertilization was intended to be effected by the succ 

 ive rising of the stamens and their bursting beside the stigma, the 

 flowers would remain merely pistillate for some twx) days before the 

 stamens came up to fertilize them. He went, however, to the other 

 extreme, believing that fertilization has always occurred, and the 

 style b&comes reflexed before the anthers dehisce, self-fertilization or 

 close-fertilization by any means being thus excluded, Henschel, 

 though far from a believer in SprengeFs views, found that before the 

 anthers of S^ Scorodonia and S. glandulosa had come to maturity the 

 style was reffexed (i, p. 103). Dr, Miiller was the first to show that 

 Scrophularia is far better fitted to maintain existence than its adapta- 

 tion for cross-fertilization alone implies ; for he found that, as has 

 been stated in describing the order of maturity of the organs, if 

 unfertilized — and this frequently occurs in damp, cold weather, when 

 insects are least active in their visits — the stigma remains in its posi- 

 tion until the stamens mature, and so, in a sense, the belief of Kol- 

 reuter and Medicus is realized. This fact is of easy observation,- 

 and no doubt accounts for the similar belief of Mr. Meehan whose 

 keen eyes detected insects upon the flowers of S. canina, but could 

 find no pollen upon the stigma of a flower until after the dehiscence 

 of its own anthers. Henslow (i,p. 371J, with a strong predisposi- 

 tion to see adaptations for regular self-fertilization, comes to the same 

 conclusion from a study of dried specimens of this species, and 

 finds his belief confirmed by what Mr, Meehan saw. Dr. Gray, like 

 Sprengel, looking at the matter' from another standpoint, seems to 

 have overlooked the provision for regular self-fertilization in case 

 crossing has not occurred, though it is to him that we owe the inter- 

 pretation of Nature's golden rule to flowers : " get fertilized, cross-fer- 

 tilized if you can, self-fertilized if you must, but at all events get 

 fertilized," Speaking of S, nodosa\i^ says: " self-fertilization here 

 can hardly ever take place7 and only through some disturbance of 

 the natural course" (4, p, 220); a similar statement is also made in 



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