Formerly, whitebait were considered to be the young of the shad; and only of late years has the misnamed fish taken its proper position. It appears that Mr. Yarrell, the able naturalist, was one morning in March struck with the early appearance of whitebait in a fishmonger's shop in St. James's; and knowing that shads, which they were supposed to be, did not make their appearance till much later (May), he took up the matter, and persevered in a course of investigation, which lasted from March to August, 1828. The specific distinction between the two fishes, on which Mr. Yarrell relies as of the greatest value, is the difference of their anatomical character; and especially in the number of vertebrÆ, or small bones, extending from the back-bone. "The number of vertebrÆ in the shad," he states, "of whatever size the specimen may be, is invariably fifty-five, while the number in the whitebait is uniformly fifty-six; even in a fish of two inches, with the assistance of a lens, their exact number may be distinctly made out."