294 BOTANICAL INFORMATION. 
burgh Catalogue. The number of species and varieties is 
thus summed up in the London Catalogue: 
Indigenous species. : . 1305 
Naturalized species — . . 94932 
Excluded species « à ei 
Varieties . " . : 2,2985 
2034 
Probably the most useful and novel feature of the London 
Catalogue, both to collectors of specimens and to botanists 
who study the geographical peculiarities of plants, will be 
found in its indications of the rarity or frequency of the 
several species. This is done by a scale of twenty figures, 
denoting the number of local floras for small tracts of 
Britain, in which each species respectively is included. Al 
though this test may not prove exact in every instance, yeb 
as a general rule, we may conclude that the more common 8 
species is, the more of such local works will it be included 5 
Through means of this scale of prevalence, assisted by the 
distinctions made between the truly and doubtfully British 
plants, the Catalogue is rendered a complete statistical sum- 
mary of the Vascular plants of Britain, in addition to 1 
more immediate purpose for facilitating exchanges of SP - 
cimens. 
Although no name is given on the cover of this “ Cata- 
logue, we think we discover the masterly hand of Mr. 
Hewett Watson, to whom British Botany is much indebted for 
the state of perfection to which it has arrived; for the care. 
with which he has studied our plants in their native wilds 
and in cultivation, so as to determine more accurately thé ag 
limits of species; for the ability he has employed in clearmg —— 
up doubtful synonymes, retaining or rejecting dubious species; — 
and above all for his writings on the geographical distribu- 
tion of British plants, which have stamped his name among 
the first in this interesting branch of science. 
The Catalogue (defaced perhaps by a few typograpbical 5 
