A. E. GIBBS—NOTES ON MOSSES. 
71 
or those in which the fruit terminates the stem, and the Pleurocarpi, 
in which the fruit is apparently lateral, though really placed at the 
extremity of an arrested branch. These two classes may he com¬ 
pared to the annuals and perennials among flowering plants; the 
acrocarpous moss simply living to produce its spores, while the 
pleurocarpous plant goes on growing and fruiting for many years. 
Besides these two great groups, there are also two other sections— 
the Amphocarpi and the Cladocarpi—represented in Britain. The 
class Musci is divided into 34 orders by Mr. Berkeley, one of our 
best museologists, to whose work I am indebted for much of the 
information contained in this paper. His arrangement is, however, 
being modified and improved upon bv Dr. Braithwaite in his ex¬ 
haustive and beautifully-illustrated ‘British Moss Flora,’ which is 
now being issued in parts. This work is a most valuable one, and 
likely to be our standard Moss Flora for a long time to come. 
Before concluding this paper it may not be out of place to allude 
to the discovery by a member of our Society of a moss new to Britain, 
although unfortunately that discovery was not made in Hertford¬ 
shire. During a visit which he paid to the Hew Forest in the 
spring of 1882, Mr. B. Piffard found a moss which he submitted to 
my friend Mr. Saunders, of Luton, for identification. That gentle¬ 
man, being unable to determine it, sent it on to Mr. H. Boswell, of 
Oxford. He immediately wrote that it was Leucobryum glaucum , 
var. minus . In July of the same year Mr. Saunders and I went to 
the Forest, one of our objects being to find out more about the 
new moss, and we were so successful as to detect it in several places. 
It is very distinct from L. glaucum , being, as the name implies, 
smaller. It grows under beech-trees principally, on the little sandy 
hillocks which are of such frequent occurrence in the Forest. I 
sent specimens to Dr. Braithwaite, and he wrote back, saying that 
he “was quite unaware that it had been found in this country, or 
even in Europe,” that it did not occur in any of the herbaria he had 
consulted except as an American plant, and that C. Mueller, the 
only modern author who mentioned it, gave only American habitats. 
He proposes to figure it in a supplementary plate at the end of the 
first volume of his ‘ Moss Flora.’ As the moss was first dis¬ 
covered by Mr. Piffard, one of our members, I think the fact is 
worthy of record in our ‘ Transactions.’ 
A PPENBIX. 
List of Hertfordshire Mosses recorded up to ls£ March , 1884. 
In this list I have followed the late Mr. E. A. Pryor’s division of 
the county into six river-districts. Ho records have been received 
from the three small districts draining into the Cam, Thame, and 
Brent. The species recorded in the Ivel district are very few in 
number, and have, without exception, been sent by Mr. Saunders, 
of Luton, to whom I am much indebted for the trouble he has 
taken in looking over and verifying many of the species I have 
found. My thanks are also due for similar kindnesses to Dr. 
