1870.] Botany. 255 



Tyrolese Alps. Owing to the shortness of the period of activity of 

 vegetation, which does not average more than from 1J to 3J- 

 nionths, few plants ripen their seeds before the return of constant 

 frost. In consequence, while the proportion of annual plants is in 

 the Mediterranean flora 42, and in that of the south-east of Europe 

 56 per cent., in the Alpine flora it is only 4 per cent. From the 

 same circumstance the flower-buds of Alpine plants are commonly 

 developed in the autumn before the return of frost, and burst into 

 bloom immediately on the melting of the snow, before the appear- 

 ance of the leaves. Another peculiarity of the Alpine vegetation is 

 the very large number of plants with rosettes of stiff succulent or 

 fleshy leaves, which both serve as ^reservoirs of food during the long 

 winter, and are also proof against the sudden evaporation caused by 

 the hot sun during the summer months. In contradistinction to 

 this, is the almost entire absence of the bulbous plants which form so 

 prominent a feature of the Mediterranean vegetation. Again, while 

 the forests of tropical countries, where the summer is long and in- 

 tense, abound with a luxuriance of climbing and creeping plants, 

 these are almost entirely absent from the Alpine flora, where plants 

 do not require to seek the shade. 



Belation behveen the Distribution of Plants and of Animals. — 

 Professor Delpino, of Florence, traces the gradual disappearance of 

 many classes of plants as one proceeds northwards, to the absence 

 of those animals, chiefly insects, which are necessary to effect their 

 fertilization. In the Tropics many plants are fertilized by the 

 agency of humming-birds, especially those possessing large trumpet- 

 shaped flowers of a scarlet hue ; and these are the first to disappear. 

 Next follow those fertilized by the larger Lepidoptera and Cole- 

 o r ptera, as roses, peonies, the night-flowering Sileneee, &c. In the 

 Arctic zone those plants only can survive which are fertilized by 

 BLymenoptera or Diptera, or by the wind ; a few flies and midges, 

 and a bee (Bombus terrestris) being the only insects found so far 

 north as Nova Zembla. In the gardens near Florence are two 

 species of Lobelia, one of which is abundantly visited by humble 

 bees, and produces seed very freely ; the other, notwithstanding its 

 beauty and the abundance of its honey, is never visited by insects, 

 and never bears seeds, but can easily be fertilized by artificial 

 impregnation. Professor Delpino believes that in its native country 

 it is fertilized by humming-birds. 



Flora of Iceland. — Professor C. C. Babington read an interest- 

 ing paper before the Linnean Society, January 20th, "On the Flora 

 of Iceland." The most recent investigations have brought up the 

 number of flowering plants indigenous to the island to about 450, 

 of which all, with the exception of about sixty, are found also in 

 Britain ; all the remainder, with three exceptions, are natives of the 

 European continent, chiefly of Scandinavia ; there is no species of 



