120 PROF. T. H. HUXLEY ON THE GENTIANS. 
of Gentians of the Actinanthe type in the Andes indicates their 
adaptability to alpine conditions; yet they are absent in the 
Alps, while well represented in the Arctic regions. 
It must be understood that I deal only with the broad facts of 
the case. Some attempts which I made to study the few forms 
which abounded at Arolla, with a view of distinguishing the 
book-species among them, became unsuccessful exactly in pro- 
portion to the number of specimens I examined; and I left off 
with the conviction that I had no means of knowing whether 
G. purpurea was distinct from G. punctata, G. campestris from 
G. germanica, or G. verna from three or four other “ species." In 
G. campestris the number of varieties in size, habit, foliation, 
form, number of parts and colour of the flower, were really asto- 
nishing; and I met with the strangest monstrosities. In @. 
verna the range of variation was quite as remarkable. If all the 
species of Gentiane are in this case, it is perilous to attempt 
numerical estimates on the foundation of ordinary collections. 
DISTRIBUTIONAL DIAGRAM. 
NORTH AncTOGZEA. 
Actinanthe. 
Keratanthe. 
Lophanthe. 
Stephananthe. 
Asteranthe. 
Limnanthe. 
Lissanthe. 
Ptychanthe. 
AUSTRO-COLUMBIA. AUSTRALASIA. Novo-ZELANIA. 
SOUTH ARCTOGEA. 
Actinanthe. — —........ (?) Actinanthe. 
Keratanthe. wee ee le eee eet et eet 
Lophanthe. Lophanthe. Lophanthe. Lophanthe 
Stephananthe. — | ........ cee ee eet ee tt 
Asteranthe. ww eee leew eee eet 
Limnanthe Limnanthe. Limnanthe. Limnanthe. 
Lissanthe. Lissanthe. Lissanthe. Lissanthe. 
Ptychanthe. Ptychanthe. wee et (e 
The names printed in black letters are those of strongly dominant types in 
the several regions. 
