$190 Tue ZooLtocist—Aveust, 1872. 
Large Pike.—A pike weighing twenty-four pounds was taken atMaple- 
Durham, on Saturday, the 24th of June, by that well-known fisherman, 
Harry Wilder.—‘ Field.’ 
Fine Salmon.—Two salmon, weighing respectively nine pounds and 
fourteen pounds and three-quarters, were taken in the Dee, at Corwen, on the 
24th and 28th of June.—Id. 
Use of the Rattles of the Rattlesnake. By J. G. HENDERSON. 
(Reprinted from the ‘American Naturalist’ for May, 1872.) 
Ir seems that the singular structure from which the subject of 
these notes derives its name was intended as a special stumbling- 
block in the path of anti-Darwinists, or to intensify the “ struggle 
for existence” which the Darwinian theory, like all other theories, 
must undergo. ~ 
In most notices I have seen of the rattles of the rattlesnake, 
they have been mentioned as though they were of no advantage to 
the possessor, and that natural selection would never produce them, 
but, on the contrary, would weed them out, if that theory were 
correct. It seems to me that the whole trouble in the matter 
arises from the assumption that the sound of the rattles, as a 
war-cry, is a disadvantage to the reptile, by calling the attention 
of its enemies to it, and thus inviting its own destruction, and 
that consequently the only way to reconcile the existence of the 
rattles with the theory of Darwin is to show that there is some 
other use made of them, and that in striking the balance between 
the profit and loss sides of the ledger the line falls on the side of 
the former, and for that reason natural selection produced and 
retains the rattles. If 1 understand him rightly, this is the view of 
the matter taken by Prof. N. S. Shaler in his paper in the January 
‘ Naturalist.’ He says that for some years he has “ been teaching 
that the tail appendage of the rattlesnake was not to be explained 
upon the theory of natural selection, inasmuch as it could contri- 
bute in no way to the advantage of the animal ; that it seemed to 
him quite clear that it was rather calculated to hinder than to help 
the creature in the race of life by warning its prey of its pre- 
sence.” But he intimates that he is now ready to say, that this 
appendage can be explained upon the theory of natural selection. 
He considers the idea that it might be used as a sexual call as 
untenable, but that the whirring sound of the rattles closely imitates 
the sound made by the Cicada, and for this reason is used as a 
