258 AUTHOR'S REMARKS ON THE 



aware of the presence of that mysterious organ the 

 hyaline stylet, situated in the centre of the foot. 

 The use of this springy muscle, which is, as we have 

 shown in the previous chapter, by naturalists errone- 

 ously considered to be the gizzard of the animal, is, 

 I believe, solely to assist the Pholas in its boring 

 operations. 



Perhaps some of my readers would like to know 

 how to procure a sight of the stylet ; if so, their 

 wishes may be easily gratified. Take up a disen- 

 tombed Pholas in your hand, and with a sharp lancet 

 or point of a pen-knife, briskly cut a slit in the 

 extreme end of the foot, and, if the operation be 

 done skilfully, the object of your search will spring 

 out of the incision to the extent, it may be, of a 

 quarter of an inch. If not, a very slight examina- 

 tion will discover the opal gelatinous cylinder, 

 which may be drawn out by means of a pair of 

 forceps. 



When extracted and held between the finger and 

 thumb by its smaller end, the stylet will, if struck 

 with a certain degree of force, vibrate rapidly to and 

 fro for some seconds, in the same manner as a piece 

 of steel or whalebone would be affected, under like 

 circumstances. l 



So long as a Pholas exhibits only the ends of its 



i In the Athenceum (Nos. 1632 and 1636), were kindly published two letters from 

 the author on the above subject, under the respective dates January 26th, and Feb- 

 ruary 28th, 1859. v 



