320 E. Jørgensen. 
the descendants of these hybrids split up according to the Men- 
delian laws one may expect to meet with numerous intermediate 
forms, wiping out the ordinary limits for the two species in 
question. The cultures necessary to decide this are, as men- 
tioned, still wanting; nevertheless I think my experiences from 
the examination of living specimens, where two distinctly different 
species were growing together, will show that such a Mendelian 
splitting is quite probable. I refer especially to tbe case men- 
tioned of E. curta X stricta (p. 40) in Eastern Norway. The 
two parents here differ in (at least) three distinct pairs of char- 
acters, viz. in the size of the flowers, in pilosity and in rami- 
fication. According to the Mendelian laws the hybrid will give 
rise to 27 different forms, of which I consider I have found 
about 7/3, though I on that occasion was only searching for 
deviating forms without thinking of their connection with those 
laws. Of these 27 forms 8 are homozygotic and will therefore 
— by mutual pollination — act as constant species. This would, 
judging from my experience, explain the remarkably numerous 
intermediate forms one finds for instance in Eastern Norway be- 
tween these two relatively well distinguished species, E. curta 
and E. stricta, forms which are striking just on account of their 
accordance with one of the species as to one character, whilst 
they agree with the other in other characters, these characters 
being interchangeable in all possible combinations in the different 
cases. This is just one of the remarkable well-known distinguishing’ 
marks of the Mendelian splitting laws. 
The same physical conditions will in the different species 
— which all must be regarded as very nearly allied, or mostly 
insufficiently distinguished — cause almost the same _ variation; 
convergent forms (in different species) are therefore quite com- 
mon, especially such as (most probably) are due to lack of 
moisture (more or less distinctly xerophile forms). 
The Norwegian species are the following: 
1. E. salisburgensis Funck apud Hoppe. The best defined 
species, differing from all the others by lack of long cilia 
at the margin of the capsule. Only found in Northern Nor- 
way, but distributed from the southern part of Nordland’s 
amt (county) to the Porsangerfjord (firth of P.), 65° 15‘— 
70° 20‘ N. Probably our oldest species, with a very dis- 
