244 Correspondence . [April, 
That the medium which is not only the vehicle, but probably 
the very substance of light and heat, if not of electricity and 
magnetism also, should be an element of vast importance in all 
cosmical phenomena, I am quite prepared to admit and main- 
tain ; but this is a very different thing from regarding it as the 
original fundamental form of matter. — I am, &c., 
H. B. 
HEREDITARY QUALITIES IN ANIMALS. 
To the Editor of the Journal of Science . 
Sir, — In considering the question of hereditary qualities in ani- 
mals, a faCt has come under my observation proving that in birds 
the peculiar note of a race is hereditary, and I forward it because 
if I mistake not one of your correspondents stated the opposite 
to be the case. 
A very young canary was purchased, and kept many weeks in 
my house ; it could not sing at all, only twit : after a while it 
made divers attempts ; most of us gave it up, but finally, in a 
month or two, it reached the perfeCt song of its race : it arrived 
at this point by stages and time, and continual practice. No 
other bird was in the house. It was a very young one when 
obtained. This seems a most decisive proof. 
Now that man is generally acknowledged to be but a “ superior 
animal,” should not the results found in animal psychicism be 
applicable to man’s mind ? — I am, &c., 
David Y. Cliff. 
