4. That a Bittor maketh that mugient noise, or as we term it Bumping, by putting its bill into a reed as most believe, or as _Bellonius_ and _Aldrovandus_ conceive, by putting the same in water or mud, and after a while retaining the air by suddenly excluding it again, is not so easily made out. For my own part, though after diligent enquiry, I could never behold them in this motion; Notwithstanding by others whose observations we have expressly requested, we are informed, that some have beheld them making this noise on the shore, their bills being far enough removed from reed or water; that is, first strongly attracting the air, and unto a manifest distention of the neck, and presently after with great contention and violence excluding the same again. As for what others affirm of putting their bill in water or mud, it is also hard to make out. For what may be observed from any that walketh the Fens, there is little intermission, nor any observable pawse, between the drawing in and sending forth of their breath. And the expiration or breathing forth doth not only produce a noise, but the inspiration or hailing in of the air, affordeth a sound that may be heard almost a flight-shot. Now the reason of this strange and peculiar noise, is deduced from the conformation of the wind-pipe, which in this bird is different from other volatiles. For at the upper extream it hath no fit Larinx, or throttle to qualify the sound, and at the other end, by two branches deriveth it self into the lungs. Which division consisteth only of Semicircular fibers, and such as attain but half way round the part; By which formation they are dilatable into larger capacities, and are able to contain a fuller proportion of air; which being with violence sent up the weazon, and finding no resistance by the Larinx, it issueth forth in a sound like that from caverns, and such as sometimes subterraneous eruptions, from hollow rocks afford. As _Aristotle_ observeth in a Problem, [SN: _Sect. 15._] and is observable in pitchers, bottles, and that instrument which _Aponensis_ upon that Problem describeth, wherewith in _Aristotles_ time Gardiners affrighted birds. Whether the large perforations of the extremities of the weazon, in the _abdomen_, admitting large quantity of ayr within the cavity of its membrans, as it doth in Frogs; may not much assist this mugiency or boation, may also be considered. For such as have beheld them making this noise out of the water, observe a large distention in their bodies; and their ordinary note is but like that of a Raven. [Sidenote: _Of Whelps._]