Chap. V. HETEROSTYLED TRIMORPHIC PLANTS. 199 



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from the same plant, have been described. Six other 

 illegitimate unions are possible, namely, between the 

 three forms and the stamens in the other two forms 

 which do not correspond in height with their pistils. 

 But I succeeded in raising plants from only three of 

 these six unions. From one of them, forming the pres- 

 ent Class V., twelve plants were raised; these con- 

 sisted of eight short-styled and four long-styled plants, 

 with not one mid-styled. These twelve plants never 

 attained quite their full and proper height, but by no 

 means deserved to be called dwarfs. The anthers in 

 some of the flowers were contabescent. One plant was 

 remarkable from all the longer stamens in every flower 

 and from many of the shorter ones having their 

 anthers in this condition. The pollen of four other 

 plants, in which none of the anthers were conta- 

 bescent, was examined; in one a moderate number of 

 grains were minute and shrivelled, but in the other 

 three they appeared perfectly sound. With respect to 

 the power of producing seed, five plants (Nos. 21 to 

 25) were observed; one yielded scarcely more than 

 half the normal number; a second was slightly infer- 

 tile; but the three others actually produced a larger 

 average number of seeds, with a higher maximum, than 

 the standard. In my concluding remarks I shall recur 

 to this fact, which at first appears inexplicable. 



Plant 21. This short-styled plant, freely and legiti- 

 mately fertilised during 1865 by illegitimate plants, de- 

 scended from self-fertilised long-, mid-, and short-styled 

 parents, yielded an average from ten capsules of 43 seeds, 

 with a maximum of 63 and a minimum of 26. Hence this 

 plant, which was the one with all its longer and many of its 

 shorter stamens contabescent, produced only 52 per cent, of 

 the proper number of seeds. 



Plant 22. This short-styled plant produced perfectly 

 sound pollen, as viewed under the microscope. During 



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