chap.vil gyno-dicecious plants. 305 



hermaphrodite flowers are strongly proterandrous, and H. 

 Miiller shows that, whilst all the stigmas on the same flower- 

 head are mature at nearly the same time, the stamens 

 dehisce one after the other ; so that there is a great excess 

 of pollen, which serves to fertilise the female plants. As 

 the production of pollen by one set of plants is thus ren- ' 

 dered superfluous, their male organs have become more or 

 less completely aborted. Should it be hereafter proved that 

 the female plants yield, as is probable, more seeds than 

 the hermaphrodites, I should be inclined to extend the same 

 view to this plant as to the Labiatse. I have also observed 

 the existence of two forms in our endemic S. succisa, and 

 in the exotic S. atro-purpurea. In the latter plant, dif- 

 ferently to what occurs in 8. arvensis, the female flowers, 

 especially the larger circumferential ones, are smaller than 

 those of the hermaphrodite form. According to Lecoq, 

 the female flower-heads of 8. succisa are likewise smaller 

 than those of what he calls the male plants, but which are 

 probably hermaphrodites. 



Echium vulgar e (Boraginese). — The ordinary herma- 

 phrodite form appears to be proterandrous, and nothing 

 more need be said about it. The female differs in having 

 a much smaller corolla and shorter pistil, but a well-de- 

 veloped stigma. The stamens are short ; the anthers do not 

 contain any sound pollen-grains, but in their place yellow 

 incoherent cells which do not swell in water. Some plants 

 were in an intermediate condition; that is, had one or 

 two or three stamens of proper length with perfect an- 

 thers, the other stamens being rudimentary. In one such 

 plant half of one anther contained green perfect pollen- 

 grains, and the other half yellowish-green imperfect grains. 

 Both forms produced seed, but I neglected to observe 

 whether in equal numbers. As I thought that the state of 

 the anthers might be due to some fungoid growth, I exam- 

 ined them both in the bud and mature state, but could find 

 no trace of inyoelium. In 1862 many female plants were 

 found ; and in 1864, 33 plants were collected in two locali- 

 ties, exactly half of which were hermaphrodites, fourteen 

 were females, and two in an intermediate condition. In 

 1866, 15 plants were collected in another locality, and these 

 consisted of four hermaphrodites and eleven females. I 

 may add that this season was a wet one, which shows that 



