54 SKETCH OF THE LIFE AND CHARACTER 
stance of the economy of nature, as we generally 
call it, but of nature’s God, who has stamped 
laws necessary for its existence and propagation 
upon the minutest insect! And this we call in- 
stinct. But this is not all; I observe that she 
excavates her central line in a horizontal direction 
as the tree grows, or across the texture of the 
vessels through which the sap passes, and the 
young larva always bore in the contrary direction, 
or along the line of the sap vessels, which seems 
to be a further mark of design ; as it is evidently 
much easier for them to eat their way in this di- 
rection, than it would be to cut across the tough 
ligneous substance of the vessels.” 
It was during his residence at Welshpool, that 
the perusal of Cuvier’s Theory of the Earth first 
awakened his interest in geology. With his usual 
activity of mind he proceeded at once to apply 
the new views he had acquired, to the objects 
immediately about him, and began to examine the 
traces of organic remains in the rocks of Powis 
Castle park. Geology and mineralogy furnished 
now the frequent occupations of his leisure hours ; 
but in these new pursuits he was left entirely to 
his own resources, having neither guide nor associ- 
ate among his acquaintance at Welshpool. He 
e 
