B racts, whioli are e ith e r slig h tly or widely different from th e
leaves, b u t usually ag reeing with th em in cell structure.
B racteoles are th e floral stipules, and are often a larg e r
modification o f tb e same.
P erianth.— T his is th e term used for th e in n e r involucre,
which is surrounded by th e female bracts. I t consists o f one
or several layers of c e lls ; in some gen era it is absent, or replaced
by th e
Calyptra, which is usually a delicate sac enclosed by tb e
p erianth.
P istillidia, or tb e female organs, are usually situ a te d a t
tb e base and enclosed by th e p e ria n th and c a ly p tra ; th e y are
oblong in shape and vary considerably in number, one only
h av in g been fertilised, developing in to th e perfect fruit, th e others
fading away.
Th e C a p su le is th e seed vessel, enclosing th e spores and
elaters, supported on a long or sho rt, usu a lly very delicate,
h y a lin e pedicel; i t is globose or cylindrical, dividing reg u la rly
in to 4 valves, e ith e r to its base or th e lower half, or ru p tu rin g
irreg u la rly . I n th e Anthooeros i t is pod-like, w ith a ru d im en ta ry
columella.
S pores or seeds v a ry in colour, shape, size, and markings.
E laters are sp ira l thread s, enveloped in a hyaline almost
invisible sac, and mixed w ith th e spores in th e capsule.
A ntheridia, or male organs, are u su a lly oval bodies, w ith
or w ith o u t a sh o rt stipe, imbedded in th e fronds or enclosed in
modified leaves called bracts.
Gemm^ are detachable cellular bodies found in some species,
which develop in to perfect p lan ts.
D is t r ib u t io n .
The Hepaticse are generally distributed throughout the
British Isles, from the sand flats and rocks by the sea-shore
to the topmost heights of our mountains, and are found in
almost every imaginable locality. They are the more abundant
in shady woods, by waterfalls and mountain streams, in bogs
or on peaty moors, growing on living and dead trees, on stone
walls and rocks or mud-covered walls; some species are peculiar
to limestone, others to subalpine and alpine districts. Full particulars
are given with each species, and if the student has any
doubt as to the determination of any species its habitat will often
afford a good clue to its correct name.
C en su s o p D is t r ib u t io n .—I have followed the admirable
arrangement adopted in the “ London Catalogue of British
Mosses and Hepaticse,” 1881.
“ The numbers 1 to 16 and the lettered numerals 17a, 17b,
18a, 18b, and 18c, stand for the twenty-one Watsonian provinces,
and show in which of those provinces each species is known to
grow. The names of these provinces, with the numbers standing
for them in the catalogue, and the counties included in each
province, are as follows :
1. Peninsular (Cornwall, Devon, Somerset).
2. Channel (Wilts, Dorset, Wight, Hants, Sussex).
3. Thames (Oxon, Bucks, Berks, Surrey, Middlesex, Herts,
Essex, Kent).
4. Ouse (North’ton, Beds, Hunts, Cambridge, Norfolk, Suffolk).
5. Severn (Monmouth, Glo’ster, Hereford, Worcester, Warwick,
Salop, and Stafford).
6. South Welsh (Glamorgan, Carmarthen, Brecon, Radnor,
Cardigan, and Pembroke).
7. North Welsh (Montgom., Merioneth, Anglesea, Carnarvon,
Denbigh, Flint).
8. Trent (Lincoln, Leicester, Notts, Derby).
9. Mersey (Cheshire, Lancashire, sine Lake Lane.).
10. Humber {YoA&hNe solus).
11. Tyne (Durham, Northumberland).
12. Lahe (Lake Lane., Isle of Man, Westmorland, Cumberland).
13. West Lowland (Dumfries, Wigton, Kirkcudbright, Lanark,
Ayr, Renfrew).
14. Hast Lowland (Berwick, Roxburgh, Selkirk, Peebles,
Haddington, Edinburgh, Linlithgow).