much slighter in build than the mallard or common wild duck; in build it is not specially a surface swimmer, but is excellently adapted for rapid progress under water. When a grebe wishes to travel swiftly from one part of the water to another it dives, swimming under water. A bird which feeds on fish must be cigar- or torpedo-shaped in order to capture its swift prey; there are no bluff bows, projecting elbows, or other obstructions on the body of the diving grebe. The general colour scheme is brown above, white beneath, but in summer the head and neck are ornamented; the dark brown crest has two elongations, known, somewhat misleadingly, as "ear tufts," though they have nothing to do with the ears. A chestnut trill or ruff surrounds the upper part of the long and slender neck; this is the tippet. Pennant, who thought that the tippet grebe was a distinct species, says: "This species has been shot on Rosterne Mere in Cheshire; it is rather scarce in England, but is common in the winter time on the Lake of Geneva, where they appear in flocks of ten or twelve, and are killed for the sake of their beautiful skins. The underside of them, being dressed with the feathers on, are made into muffs and tippets; each bird sells for about fourteen shillings." For diagnostic characters he states that this species is rather smaller, lacks crest and ruff, and "the sides of the neck are striped downwards from the head with narrow lines of black and white." It is evident that Pennant's Rostherne bird was immature, still having the striped neck markings which are characteristic of all young grebes. The trill and full tufts are lost in winter, though indication of the latter can be seen at all seasons on mature birds. Thus Pennant's tippet grebe was without tippet; it was the silvery breast, suitable for tippets, which gave it the name.
The adaptability of the grebe for rapid subaqueous
