THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
39 
subordination of groups lias arisen by evolution, and we 
have here, therefore, a very strong argument that in the 
creation of organic beings the same laws have prevailed. 
In the comparison between the division of organisms and that 
of languages we find yet another similarity. We find that in 
both the differences between members of the same group have 
not always the same value. For example, if we take several 
species belonging to the same genus, we may find some very 
much alike and others much more different. The same is 
the case with orders of the same class, with classes of'tlie 
same sub-kingdom, and so forth ; likewise we find in languages 
that dialects of the same language differ in a variable degree 
from each other, as also the different languages belonging to 
one group, &c. 
Another strong argument in favour of the evolution 
theory is derived from the fact that allied groups of animals 
or plants show their relation most by resemblances of their 
lowest representants. When you compare the species of one 
group with those of an allied one, you find the greatest 
difference in the most modified and specialised, whilst the 
simplest and least changed forms will show a greater simi¬ 
larity. Now that is exactly what follows as a necessity from 
the theory of evolution. Two groups which are allied will 
by descent and divergent modification give rise to a number 
of sub-groups, and it is in the least modified members of each 
sub-group that we should look for the most numerous points 
of similarity, which, as we have seen, is actually the case. 
With these facts and the different analogies between 
languages, known to have arisen by evolution, and organisms, 
we must come to the conclusion that the latter, too, have been 
produced by a process of evolution, and the truths derived 
from classification form at least a very strong argument in 
favour of that conclusion. 
THE MIDDLE LIAS OF NORTHAMPTONSHIRE. 
BY BEEBY THOMPSON, F.G.S., F.C.S. 
PART I. 
(Continued from page 23.) 
To the north and north-east of Watford there are very few 
Middle Lias Sections to be seen. Of those mentioned in the 
“ Memoirs of the Geological Survey,” I have only been able to 
find one, that at Elkington. A little north of Elkington a 
