ES a | | ees 
Trigonella-formation is seen, in the line before the last, and 
in the remaining lines the spectra, (arranged by me after the 
lists of the named authors), of various arctic and alpine fell- 
fields, and finally, (last of all), a desert spectrum. The fact 
might be emphasized that the fell-field spectrum may not 
specially express the vegetation natural to fell-field formations, 
but to that of arctic and alpine nature; for, as RAUNKIAER 
has shown, hemicryptophytes and chamaephytes dominate in 
just that nature, — the latter thriving the better the poorer 
the conditions, i. e. the greater the altitude, or the further 
north. However, this reservation in no way alters the main 
point that all the spectra given, agree in having a large per- 
centage of hemicryptophytes and chamaephytes, and from 
this we may conclude that the spectrum both of the Trigo- 
nella-formation and of the others is an expression for alpine 
nature. 
In other words the ability of the plants of Pamir to 
adapt themselves to their surroundings, in so far as this 
regards the relation of the surviving apices to the crust of the 
earth, is an adaptation to cold and snow, rather than to heat 
and drought. 
A further comparison between the Trigonella-formation 
and fell-fields!) reveals the following similarities and differ- 
ences. 
1) According to WARMING, 1909, the characteristic of fell-field is the 
fact that all vegetation is low, and that plants are so far separated from 
each other that the bare ground is visible between. In arctic fell-fields there 
are often many mosses and lichens which are either rare or totally wanting 
in alpine fields from lower latitudes. Fell-fields are to be found on almost 
all high mountains, ‘Warming’s description of fell-field, (1909, page 256), 
might have been written on a New Zealand dry mountain”. (SPEIGHT & 
COCKAYNE, 1911.) The conception fell-field includes many various formations, 
from the arctic fell-field, which is closely related to “Tundra”, to the “Ge- 
steinsfluren” of the Alps (SCHROTER) and the xerophytic vegetations in the 
mountains of Pamir, New Zealand, and many other places, They are all 
rich in chamaephytes, poor in therophytes, and wanting in fanerophytes, 
however different they may be in other respects. To give them the com- 
mon name “‘fell-field”, is at present just as permissible as to group many 
different formations under the term “forest”. 
