130 EVIDENCE OF DESIGN, 
precision. Many things, for instance the claw leg of 
the crawfish, will replace itself exactly when destroyed, 
but the feather alone repairs its own breaks precisely and 
automatically. 
“Taken as a whole, the feather is one of the most 
perfect products of nature because the material used is 
the one best thing throughout, the engineering principles 
involved are without fault, the mathematical plan is pre- 
cise, the construction is perfect, the coloring and artistry 
are flawless, and there is not one single point about it 
that can be constructively criticized. 
“This short article can only hint at the wonderful 
things one may find in a single feather, and it is something 
well worth not an hour, but weeks or months of the most 
painstaking and careful study, for it covers an amazing 
field.” 
The electric battery in certain fishes is so palpable a 
case of design that Charles Darwin admitted his in- 
ability to account for it by Natural Selection. The elec- 
tric ray, or torpedo, for instance, has been provided with 
a battery which, while it closely resembles, yet in the 
beauty and compactness of its structure, it greatly ex- 
ceeds the batteries by which man has now learned to 
make the laws of electricity subservient to his will. In 
this battery there are no less than 940 hexagonal columns, 
like those of a bee’s comb, and each of these is subdivided 
by a series of horizontal plates, which appear to be ana- 
logous to the plates of the batteries used in automobiles. 
The whole is supplied with an enormous amount of ner- 
vous matter, four great branches of which are as large 
as the animal’s spinal cord, and these spread out in a 
multitude of thread-like filaments round the prismatic 
columns, and finally pass into all the cells. “A complete 
knowledge of all the mysteries which have been gradually 
unfolded from the days of Galvani to those of Faraday, 
