238 Lord Justice Fry [Jan. 23, 



From the table it will be further seen that the larger group of 

 the Muscinea3 divides itself into three principal smaller groups ; the 

 Hepatica) or liverworts, the SphagnacesB or turf mosses, and the Musci 

 or true mosses — urn-mosses, as they have been called, from the form 

 of their capsule. Passing over the other subdivisions, it may be 

 observed that the Acrocarpous mosses are those which carry their 

 capsules at the end of the axis of growth, whilst the Pleurocarpous 

 mosses bear their fructification on stalks, more or less long, proceed- 

 ing from the sides of the axis. Amongst these Pleurocarpous mosses 

 occurs the old genus Hypnum (broken up by modern systematists 

 into several genera), the largest of all the genera in these islands 

 or in Europe — a vast group which occupies amongst mosses something 

 like the place which the Agarics occupy amongst the Fungi. 



Number of British S'pecies. — If we were to try and ascertain the 

 number of the British Muscineae from the systematists of some few 

 years ago, like Hooker and Wilson, the species would number be- 

 tween 500 and 600 ; but according to the views of more recent 

 writers, the number would probably rise to something between 800 

 and 900. The true mosses are the most numerous, the turf-mosses 

 by far the fewest. 



Date of Flora. — "What is the date of this moss flora of Britain ? 

 Two ancient collections enable us to give some reply to the question. 

 In an interglacial bed near Crofthead, in Kenfrewshire, eleven 

 species of moss were discovered, and with one possible exception all 

 are well-defined British species of the present day. If we take 

 Mr. Wallace's chronology, and hold that 80,000 years have passed 

 since the Glacial epoch disappeared, and 200,000 years since the 

 Glacial epoch was at its maximum, we may perhaps give from 100,000 

 to 150,000 years for the age of this little collection. Out of the 

 eleven mosses discovered, seven belong to the genus Hypnum, or the 

 family Hypnaceae. This collection, then, is evidence, so far as it 

 goes, (1) that the existing moss flora is as old as the interglacial 

 epoch ; (2) that the Hypnaceae were as dominant then as now : and 

 (3) that the specific forms have remained constant since that epoch. 



Another collection of fourteen mosses has been discovered in a 

 drift in the Clyde valley above the Boulder drift, and tends to 

 confirm the previous conclusions ; as all the species are existing, all 

 now inhabit the valley of the Clyde, and the HypnaceaB are still pre- 

 dominant, though not in so great a proportion as in the Eeufrewshire 

 bed. 



The fossil remains of mosses are not numerous, nor for the most 

 part very ancient. Heer inferred their existence in the Liassic period, 

 from the presence of remains of a group of small Coleoptera, the 

 existing members of which now live amongst mosses — an inference 

 which seems not very strong. But recently the remains of a moss 

 have been found in the Carboniferous strata at Commentry, in 

 France. It appears to be closely allied to the extant Polytrichura, 

 the most highly-developed genus of mosses ; so that we have here a 



