Natural History. — Zoology. S7S 
dones might be called Dighies^ because they have two surfaces 
of growth ; the monocotyledones, which have only one, might 
be named Monogenes ; and the agamic or cryptogamic plants, 
Agenes, — Bullet. UniverseL 
ZOOLOGY. 
^7. Occasional Abundance and supposed Migrations Field- 
Mice. — Field-mice appeared in extraordinary numbers in Mor- 
vern, about the year 1809 or 1810. They were first observed in 
the month of August, and disappeared during the ensuing winter. 
They were most numerous in the north, on Loch Sunart side of 
Morvern, where the country is wildest and most rugged, and 
where there is least arable land. On the coast of the Sound of 
Mull, their numbers w^ere comparatively trifling. They also 
infested the districts of Sunart, Ardnamurchan, Moidart, Ari- 
saig, and Ardgour. In Morvern, during the months of August 
and September, any spot of fine pasture in the hills was cut in 
roads, close to the ground. The grass cut by the root lay 
withered. Bushes were also cut by the root, in the same way ; 
and the white interior substance gathered in heaps for nests. 
About the end of October and beginning pf November, in 
woods and low grounds preserved for winter grazing, the grass 
was found cut in the same way as in the hills. The bark of 
young wood was frequently gnawed off, and the ground per- 
forated to such a degree, in making their subterraneous resi- 
dences, that it often yielded to the foot in walking. These 
subterraneous residences, it is supposed, were intended for win- 
ter quarters. It was observed, that the nests of the mice, above 
and below ground, all communicated with each other, by an 
amazing number of these cross-roads, formed by cutting the 
grass close to the ground ; and every nest was invariably con- 
nected, by means of these roads, with some place where there 
was water. In Morvern, and it is believed in every quarter which 
the mice infested, they were most numerous in those farms 
where there is least crop ; and, upon the whole, they destroyed 
much less crop than grass. This did not proceed from a want 
of relish for com diet ; for, in one farm in Morvern, where there 
is very little arable ground, the crop was completely destroyed. 
Even eveiy square foot of the roof of the barn was perforated ; 
and a great mau^ of the stobs (sharp-pointed rods for fastening 
