Note 82 — IX.

Such is the common statement. Dr. Harlan, however, observes that "the rattle is cast annually [with the sloughed skin], and, consequently, no inference as to the age of the animal can be drawn from the number of pieces which compose the rattles." (Journ. Acad. Nat. Sci.; v. 368.) I confess this appears to me to be a non sequitur; for is it not quite possible that one may be added to the number annually, without involving the actual perpetuity of the preceding ones? It is evident that the increase must take place at some time or other, and it seems to me more likely to occur at the sloughing of the skin, that is, annually, than either oftener or seldomer.