INFLUENCE OF ELEVATION. 



509 



Viscaria), and a third whose stem bears alternate leaves and whose flowers are 

 grouped in capitula (Pyrethrum corymbosum). 



The Grass of Parnassus (Parnassia palustris) from the Alpine garden, when 

 compared with plants grown in the experimental beds of the Vienna Botanic 

 Garden, showed the following measurements: 



In the Alpine regions, therefore, the plant was only J or J as high and the leaves 

 only J-J as large as in Vienna, whilst the flowers in the Alpine region had a much 

 smaller diameter than in Vienna. 



Comparing the hermaphrodite plants of Lychnis Viscaria in the experimental 

 garden of the Blaser with those of the same species at Vienna, we obtain the 

 following: 



Vienna Botanic Garden. 



: Experimental Garden on the Blaser. 



Height of the stem, including ) 

 the axis of the inflorescence } 



Dimensions of lower leaves 



Inflorescence 



Calyx 



Lamina of petals 



Claw of petals 



400-500 mm. 



80 mm. long, 4 mm. broad. 

 80 50 

 15 6*5 



10 8 

 8 mm. long. 



230-240 mm. 



50 mm. long, 3 mm. broad. 

 60 40 

 13*5 5 

 8 6*8 

 7 mm. long. 



Plants from the Alpine garden, therefore, when compared with those from the 

 Vienna Botanic Garden, exhibit smaller measurements of stem, leaves, and flowers. 

 The following points were also noted: the number of internodes in plants from 

 the Vienna Garden was 9, of which 5 were on the axis of the inflorescence; each 

 cyme consisted of 3-5 flowers, and the whole inflorescence bore 33-40 flowers. 

 Plants from the Alpine Garden had only 6-7 internodes, of which 3 belonged to 

 the inflorescence; the cymes composing the inflorescence were only occasionally 

 3-flowered; in most of them only the central flower developed, the two lateral ones 

 being suppressed. The whole inflorescence included only 5-11 flowers. 



Plants of Pyrethrum corymbosum, from the Alpine Garden, compared with 

 those from the Vienna Botanic Garden (all raised from one batch of seeds) showed 

 the following differences: 



