Chap. I. 



PRIMULA VEEIS, 



21 



my anticipation that the plants with longer pistils, 

 rougher stigmas, shorter stamens, and smaller pollen- 

 grains, would prove to be more feminine in nature, is 

 exactly the reverse of the truth. 



In 1860 a few umbels on some plants of both the 

 long-styled and short-styled form, which had been cov- 

 ered by a. net, did not produce any seed, though other 

 umbels on the same plants, artificially fertilised, pro- 

 duced an abundance of seed; and this fact shows that 

 the mere covering in itself was not injurious. Accord- 

 ingly, in 1861, several plants were similarly covered i 

 just before they expanded their flowers; these turned 

 out as follows: — 



Table 5. 



KmnlMr of 

 UmbeU 

 produced. 



Frodact of Seed. 



Short-styled . 

 Long-styled . 



6. 



18 



S4 



74 



f 1.3 grain weight of seed, or 

 I about 50 in number. 



Not one seed. 



Judging from the exposed plants which grew all round 

 in the same bed, and had been treated in the same 

 manner, excepting that they had been exposed to 

 the visits of insects, the above six short-styled plants 

 ought to have produced 93 grains' weight of seed 

 instead of only 1.3; and the eighteen long-styled 

 plants, which produced not one seed, ought to have 

 produced above 200 grains' weight. The production of 

 a few seeds by the short-styled plants was probably due 

 to the action of Thrips or of some other minute insect. 

 It is scarcely necessary to give any additional evi- 

 dence, but I may add that ten pots of polyanthuses and 

 cowslips of both forms, protected from insects in my 

 greenhouse, did not set one pod, though artificially fer- 



