602 Sir John Luhhoch [Feb. 18, 



maturity they erect themselves (Fig. 3 c), stand up boldly above the 

 rest of the plant, and open by the three equal valves (Fig. 4) re- 

 sembling an inverted tripod. Each valve contains a row of three, four, 

 or five brown, smooth, pear-shaped seeds, slightly flattened at the upper, 

 wider end. Now the two walls of each valve, as they become drier, 

 contract, and thus approach one another, thus tending to squeeze out 

 the seeds. These resist some time, but at length the attachment of 

 the seed to its base gives way, and it is ejected several feet, this being 

 no doubt much facilitated by its form and smoothness. I have known 

 even a gathered specimen throw a seed nearly 10 feet. Fig. 5 repre- 

 sents a capsule after the seeds have been ejected. 



Now we naturally ask ourselves what is the reason for this difference 

 between the species of violets ; why do V. odorata and V. liirta conceal 

 their capsules among the moss and leaves on the ground, while 

 F. canina and others raise theirs boldly above their heads, and throw 



Fig. 4. Fig. 5. 



Viola ca?ima— seed-vessel Viola canina — seed-vessel 



with seed. after ejecting the seed. 



the seeds to seek their fortune in the world ? If this arrangement be 

 best for F. canina^ why has not F. odorata also adopted it? The 

 reason is, I believe, to be found in the different mode of growth 

 of these two species. 



F. canina is a plant with an elongated stalk, and it is easy there- 

 fore for the capsule to raise itself above the grass and other low 

 herbage among which violets grow. F. odorata and F. liirta, on the 

 contrary, have, in ordinary parlance, no stalk, and the leaves are 

 radical, i. e. rising from the root. This is at least the case in appear- 

 ance, for, botanically speaking, they rise at the end of a short stalk. 

 Now, under these circumstances, if the Sweet Yiolet attempted to shoot 

 its seeds, the capsules not being sufficiently elevated, the seeds would 

 merely strike against some neighbouring leaf, and immediately fall to 

 the ground. Hence, I think, we see that the arrangement of the capsule 

 in each species is that most suitable to the general habit of the plant. 



