35 
and incomplete an obstacle as a lock forming a boundary line 
between varieties, and even kinds of shells, gives us some limit 
about the apparently small lines of demarcation which may 
determine the complete range of species and even genera upon 
the surface of the globe. Our second reflection is upon the 
instability of species, and the impossibility of any cut-and-dried 
definition of the term. Of course a natural history which 
ignored species would be as absurd as a thermometer ungraduated 
—only species are best regarded in the same light, merely 
degrees marked upon the unbroken flow of life. The third 
reflection is how species are affected by a change of circum¬ 
stances, and that, though the change is often far from being 
very obvious. No one would suppose that the difference in the 
quality of the water in the Ouse and the Foss is so great as 
the difference between the two forms of Anodonta living within 
a few yards of one another shows it to be. A superficial 
and special view of any department of natural history leads 
to the conclusion that Nature has, as it were, a number of 
moulds from which she is never tired of producing the same 
forms. A wider and more general view, extending to past 
geological epochs, reveals the great fact, that as the individual, 
so too the species and the genus, have their birth, their vigour, 
their decay, and their death, and that natures moulds them¬ 
selves are as impressionable as the receiving surface of the 
photograph—not one external influence but evokes a corres¬ 
ponding modification. 
April 4th, 1882. —In the absence of the Author, the Fev. 
Canon Raine, M.A., read a paper by the Rev. C. W. King, 
M.A., Trinity College, Cambridge, on “ the Roman Statue 
found in York, in 1880.”—The statue of some personage 
arrayed in complete Roman armour, lately discovered at York, 
is incomparably the finest example of Roman-British workman¬ 
ship that we possess, from its excellent style, exceptional 
magnitude, and wonderful preservation. What adds im¬ 
mensely to the interest of the relic is the assurance that it 
was the production of native skill and not an importation from 
a region more advanced in culture (which its merit might 
