VOL. XLI.] PHILOSOPHICAL TRANSACTIONS. 381 



other, there is a sort of cavity ; and in these sides the harder fibres may be 

 distinguished, disposed in such a manner, as perfectly to resemble the gills of 

 fish : and through them the worm seems to breathe. 



The extreme softness of the other parts of the head prevents our coming at 

 the knowledge of the use of the membranes, furnished with fibres of different 

 tendencies, or inquiring by what organs the worm takes the wood shaved off by 

 the hemicrania, or rough shells ; whether it does this by suction, or not ; by 

 what muscles, or how acting, this wonderful head is moved. It is probable in- 

 deed, that its motion consists in the opening and closing these shells, that shave 

 off the wood ; and that the inner parts have a power to move on all sides, as 

 the ball does in the spcket of the eye ; and perhaps to come forth of these 

 shells, and re-enter, after taking their food. But of these things there can be 

 no certainty, because the parts dissolve between the fingers. 



The body, viewed forward, fig. "J, is of a reddish colour. In the middle ap- 

 pears a line, often dark-brown, often blackish, sometiines not visible, some- 

 times running near half the length. The rest of the animal is of a whitish or 

 grey colour. ]. If you intend to dissect it, and examine the inside, you must 

 first remove a thin membrane surrounding the whole body, which for that rea- 

 son may be called the cutis or cuticula. When this is removed, there appears 

 an oblong vessel placed in the middle, of a reddish colour, from the shaved 

 wood, of which it is full: hence it seems to be the stomach, or at least the first 

 organ of digestion. 2. In the lower part you will find another vessel, appear- 

 ing like a dark-brown line, which contains the excrements, of which it is often 

 found full, and discharges them at the end of the tail. 3. At the sides of the 

 reddish vessel, or stomach, is placed a white, clammy, fat substance, sticking 

 to the fingers, and perhaps constituting the flesh of the animal. 



Where the body ends, the tail begins, thicker than the body, and rendered 

 stronger by circular fibres. At its end it has two small hard bodies, containing 

 and defending the tender extremities of the tail. This tail, thicker than the 

 body, terminates in two ends, the thickest of which certainly serves for the 

 discharge of the excrements, the slenderest doubtless for generation : and this 

 it can stretch out to an incredible length, so that in worms that seemed to be 

 in copulation, it appeared above an inch out of the pile. The two small bodies, 

 that contain these ends of the tail, are of a harder substance than even the 

 hemicrania. The outer part is gibbous, the inner hollowed. The lower end is 

 bifid ; whence it is conjectured, that they serve the animal for feet, when it is 

 mounting upright, or corroding the wood ; by leaning on them as on a prop, 

 fig. 13. 



The above- described worm dwells now very securely in a testaceous tube, of 



