12 THE DISTRIBUTION OF HEPATIC IN SCOTLAND 
It would be a very different matter if a census of the 
number of individual plants within equal areas of the dry 
and wet districts were taken. 
The apparent absence of Atlantic species of Lejewnew, and 
some other species of the same type, from the low ground 
of South-West Scotland is most probably due to the small 
annual rainfall, as some of them occur in the neighbouring 
wetter districts at the foot of the hills, although further 
from the sea, the geological formation being the same. 
Few of the Atlantic species are found below 30 in. They 
are most common in that part of the coast which has 
between 50 and 70 in. 
None of the following Lejeunee have been found 
under the 40-in. rainfall, viz. calyptrifolia, microscopica, 
Macvicari, hamatifolia, and ovata. To these should be 
added L. minutissima, but this species has only been found 
in two localities in Scotland and cannot be taken into 
account in this regard. It is not a purely Atlantic species, 
and it occurs in England, where it is less rare, in some 
localities under the 40 in. 
Subalpine species are uncommon below 40 in. except 
in the proximity of mountains and in the extreme north, 
especially Shetland, where latitude has some effect. The 
peat-moss species, as already stated, have a wide range in 
rainfall. The subalpine species Preissia quadrata, 
Lophozia Muelleri, and Scapania subalpina have been 
found on moist ground in sand-dunes below the 30-in. 
rainfall. 
LATITUDE 
LATITUDE in Scotland hardly affects the actual presence of 
any of our low-ground species of hepatics except in the case 
of the thalloid genera of Southern type, Riccia, Targionia 
and the introduced Lunuluria and perhaps a very few 
foliose species also of the same type, as Bazzunia trilobata, 
Madotheca levigata, and Cephalozia Francisci. The 
absence in the extreme north of some of our other low- 
ground foliose species is in all probability due to the 
absence of shelter, as they are all plants of moist sheltered 
