32 
FIFTY YEARS OF BOTANY IN BRISTOL. 
W. B. Waterfall — both well known members of the B.N.S. — are 
living authorities quoted by Mr. Watson. Of the 619 known 
British species it is stated that some 300 occur in Somerset ; and 
it has been computed that at least 200 of these are to be found 
within walking distance of our city. 
On the Gloucestershire side of the district, work among the 
mosses has not hitherto been so systematic. Dr. G. H. K. 
Th\vaites, the most able Bristol botanist of his day, explored the 
neighbourhood very thoroughly ; and it is said that his herbarium 
contained nearly all the plants that are now known in the area 
he visited. That important collection, however, at one time in 
the Museum of Clifton College, has most unluckily been lost. 
The moss- flora of Gloucestershire is now in the hands of Mr. H. H. 
Knight, of Cheltenham. He has the task of eliminating error, so 
far as practicable, from the available records, and expects in a 
short time to furnish an adequate statement of the facts. Mr. 
Knight writes that the following mosses of especial interest have 
been found in recent years on the Gloucester side of the Avon, 
about St. Vincent's Rocks and Durdham Down : — Pottia bryoides 
(Miss Roper). Weisia calcarea var. viridida (W. B. Waterfall). 
W . crispa and W. crispata (Miss Roper). Barbula Hornschuchiana 
(J. W. White). Pleurochaete squarrosa and Heterocladium heter- 
optcrum var. fallax (W. B. Waterfall). 
Hepatic^. The Scale-mosses or Liverworts. "A group of 
plants, not very conspicuous, not to everyone very familiar, but 
common, and, in some cases, very elegant, and in all cases very 
interesting ; things not of interest only, but of beauty. 
. And even those forms amongst them which have the least 
obvious elegance, are full of hidden beauties that only await the 
loving observer to give pleasure and joy."* Yet, with a few 
notable exceptions, they have been but little appreciated by local 
botanists. Out of the 4,000 odd species that have been enumerated 
in the world, about forty are known to grow in the Bristol district. 
Our member, Mr. E. H. Read, who has studied the subject "not 
from a statistical or historical side, but for the interest of the 
plants, themselves," thinks that the record of local species might 
be sensibly lengthened on further close investigation. He gives 
two main reasons for the apparent neglect of this group. Firstly, 
many of them are so tiny, requiring keen eyesight and diligent 
search for detection, while their homes are often in places dripping 
with water that do not commend themselves to naturalists chary 
of wetting their feet ! Secondly, it is only within the last two 
years that a handbook within the reach of a modest pocket and 
containing such reliable descriptions of the plants as should enable 
an average botanist to identify them, has been available. As rare 
species growing with some frequency near the city or on Mendip, 
Mr. Read mentions Lejeunia Mackaii, Reboullia hemisphcerica, 
* The Liverworts, British and Foreign. By the Right Hon. Sir 
Rdw. Fry, G.C.B., and Agnes Fry, 1911. 
