206 
president’s address. 
of the Secondary, is an insuperable objection to the supposi¬ 
tion that tlie latter is the natural outcome of the former. 
But it lias always seemed to me that sucli objections are 
extremely feeble. Every new addition to our knowledge may 
fairly be expected to supply us with missing links ; to ask 
for them at present is unreasonable, considering the very 
small portion of the surface which has as yet been explored. 
As an instance of how an organism, though actually existing, 
may easily escape our most careful research, I would briefly 
mention certain minute bodies found some years ago in the 
Downton sandstone, and which were long supposed to be the 
capsules of a Lycopodium. Careful examination, however, of 
microscopic sections of these bodies shows that they are 
composed of an alga, closely resembling the modern Rivularia , 
and that this has been invaded, as sometimes still happens, by 
another, almost, if not quite, identical with the ('Edogonium , 
which exists this day in our lakes and rivers. But for the 
chance blow of a geologist’s hammer in an exposure, not three 
yards square, in one of the shrubberies of Downton Castle, 
we should never have known of the existence of this link 
between the present and a remote past. No one can reason¬ 
ably doubt that, although as yet undetected, this fragile plant 
never ceased to exist somewhere, through all the mighty 
changes of which this earth has been the scene, and that it 
thus furnishes a strong argument in favour of the continuity 
of life. Another instance of the removal to an earlier date 
than had previously been known of the existence of an 
organism is supplied by the discovery of Lithodomus borings 
in the Aymestry limestone by my friend, Professor Corfield. 
From his acquaintance with the Oolitic formation, in which 
specimens of these abound, he was struck by the resem¬ 
blance to them of certain pits or depressions in the surface 
of the corals which abound at Weo Edge. Sections of the 
specimens collected by him are now in a case at the 
Kensington Museum, and figures of these appear in the 
“Geology of Shropshire” lately published, clearly showing 
the bivalve lying in the pit which it has burrowed into the 
coral. And, lastly, the manifold remains found in that 
most remarkable deposit, called the Ludlow bone-bed, an 
exposure of which at Norton I hope some of us may visit to¬ 
morrow, bear striking testimony to the remark that vast 
multitudes of animals must have abounded during long 
periods of time, which have left little or no trace of their 
existence. Germane to this subject is the discovery within 
the last year of insects and scorpions in rocks of Silurian age 
in Scotland, France, Sweden, and America. The first of 
these consists of a wing of a Blatta, or cockroach, from the 
