355 



stemless violets, including the odorous species, it is lancet-shaped, in 

 a few only being linear. 



7. Geographical distribution of VioletSj according to their Nec- 

 taries. — 



" Violets are found in most parts of the world, though their distribution is influ- 

 enced materially by climate. The species from tropical countries are mostly from 

 localities where the influence of elevation has neutralized or modified the climatal in- 

 fluence. The various sections of the genus have geographic centres, as may be seen in 

 the congregations of the allies of hirta in North America, and of those of tricolor in 

 alpine Europe. North America may be looked upon as the capital of the whole genus, 

 since we find there representatives of all its subdivisions. , In the following table the 

 distribution of 75 species, according to the form of their nectaries, is exhibited : — 



Lancet-shaped . . Europe, 19 Asia 4 Africa 1 N. America 22 S. America I Australia 1 Total 46 



Rotund 2 1 1 4 



Linear 12 4 I 6 23 



8. Applicatioti of the above considerations to the arrangement of 

 the Violets. — 



" To group the violets according to the form of the nectary, without considering 

 the relation of that form to the other characters of the plant, would be to arrange them 

 artificially and not naturally; for then we should have such violets as ochroleuca and 

 prionantha associated with the pansies, and other combinations of a similarly unnatu- 

 ral character. But associating the form of the nectaries, with that of the leaf, with 

 the colour, and with the geographical distribution, we obtain a very natural arrange- 

 ment of the species. The odorous and hairy violets, presenting short lancet-shaped 

 nectaries, cordate leaves, often being hairy, and frequently nearly orbicular, purple- 

 blue flowers, no stem, and a centralization of the species in North America, form a 

 first group. The same form of appendage, but usually more developed as to length, 

 combined with a cordate or lanceolate leaf, smooth, or slightly hairy, a stem, purple- 

 blue or cerulean flowers, and an almost equal distribution in the old and New Worlds, 

 indicate a second equally natural, which may be represented by V. canina. V. palus- 

 tris is the type of a third, and V. bifiwa oi & fourth ; the former associating a reniform 

 leaf with a rotund appendage and a cerulean flower, and the latter a similar leaf with 

 an abbreviated lancet-shaped appendage and a yellow flower. The linear nectary, 

 combined with a yellow flower and cordate leaves, fonns a. fifth; parallel to which may 

 be placed (sixth) such as have pinnate leaves, blue flowers and linear nectaries. Last- 

 ly, the pansies fonn a most natural group (seventh) of themselves, presenting us with 

 flowers of all colours, linear nectaries, leaves peculiar to themselves, lyrate stipules, 

 and a centralization in the mountainous countries of the western portion of the Old 

 World."— p. 81. 



XI. An Attempt to ascertain the true Hypericum quadrangulum of Linneeus. 

 By Charles C. Babington, M.A., Cantab., F.L.S., F.G.S., &c. 



The author observes that the difficulty attending the determination) 

 of the Hypericum quadrangulum of Linnaeus, has arisen from a belief 



