Sir John Lubbock’s Address. 287 
But if these figures show how rapid our recent progress 
has been, they also very forcibly illustrate the imperfection 
of the geological record, and give us, I will not say a meas- 
ure, but an idea, of the imperfection of the geological record. 
The number of all the described recent species is over 800,000, 
but certainly not half are yet on our lists, and we may safely 
take the total number of recent species as being not less than 
00,000. But in former times there have been at the very 
least twelve periods, in each of which by far the greater num- 
ber of species were distinct. True the number of species was 
probably not so large in the earlier periods as at present; but 
if we make a liberal allowance for this, we shall have a total 
of more than 2,000,000 species, of which about 25,000 only are 
as yet upon record; and many of these are only represented by 
a few, some only by a single specimen, or even only by a 
fragment. 
The progress of paleontology may also be marked by the 
extent to which the existence of groups has been, if I may so 
say, carried back in time. Thus I believe that in 1830 the 
been accomplished during the half-century. 
ds the Arctic regions, in the year 1830 the coast 
