Miscellaneous. 521 



shrink more and more in size and shape as they reach greater eleva- 

 tions. Both these facts hoar witness to the influence of climatal 

 conditions on tlie development of vegetable life. 



Cereals occur exclusively on the detrital soils of the lower region. 

 They follow the Alpine tertiary gravel in its variations of altitude ; 

 but are only able to produce a rich harvest where they grow on a 

 detrital soil composed of lime, alumina, and silica mixed in nearly 

 equal proportions. This same soil is likewise the most congenial to 

 the non-cultivated plants of the lower region. If this soil be mixed 

 with heterogeneous substances (as salts, on the sea-shore, on the 

 banks of saline lakes, on plains with saline efflorescence, or above 

 saliferous rocks), new genera and species, not occurring under ordi- 

 nary circumstances, make their appearance. 



The pine {Pi/ius abies, L.) accommodates itself to every soil, and 

 therefore ranges from the lower to the upper region, marking the 

 limits between, and participating in both. Its vertical oscillations 

 correspond to those of the cereals, and to the distribution of detrital 

 soil accessible to atmospheric heat. 



New vegetable forms, together with new rocks, make their appear- 

 ance in the higher rocky regions. Such are certain species peculiar 

 to the calcareous mica-schist, as Artemisia nana. Sand., Lomuto- 

 ffonium curinthiacum, Rehb., Gentiana jn'ostrata, Ilaeuke, Hernia 

 aria alpina, L., Braya alpina, Iloppe, <S:c. 



Wherever a great variety of rocks near to, or interstratified with, 

 each other appear within a comparatively narrow space, the plants 

 pass from one of these soils to another, undergoing at the same time 

 frequent alterations of form ; species nearly allied to each other are 

 peculiar to such spots, producing hybrid and intermediate forms. 



The distribution of genera and species in the upper region answers 

 exactl}^ to the geological constitution of the soil. Calcareous and 

 mica-schist«se Alps have every one their pecvdiar flora. Near Win- 

 disch-lNIatzey and Heiligenblut the mica-schist and the calcareous 

 mica-schist floras appear side by side. At the "Tauern" of Rad- 

 stadt, where nearly all Alpine rocks are heaped together, the floras 

 of the calciferous rocks, of the mica-schist and of the calcareous mica- 

 schist appear simultaneously. 



M. Stur appended to his memoir a catalogue of about 1000 species 

 of plants collected by him within the Alpine region, and arranged 

 according to their localities and to the geological constitution of 

 their native soil. 



Note on the Freshwater Dolphins of South America. 

 By M. Paul Gervais. 



It has long been known that a peculiar species of Dolphin is an 

 inhabitant even of the upper parts and branches of the great river 

 Amazon, to the Indians living on the borders of which it is a creature 

 of no small importance. It w^as described by M. d'Orbigny as the 

 type of a new genus under the name of Inia boliviensis, by which 

 it has since been generally known ; but it appears to have been 



Ann. ^ Mag. N. Hist. Ser.2. Fo/.xvii. 34 



