290 EVENINGS AT THE MICROSCOPE 



of the quadrantic mass just described. At the ventral 

 extremity they are articulated to a slender fulcrum, which 

 is a little bent downward. The solid framework of each 

 ramus sends off, from its inferior surface, a slender curved 

 process, which is connected with the extremity of the ful- 

 crum. 



The action of this apparatus is as follows: The ciliary 

 vortices produced by the waves of the coronal disk pass 

 together through the upper sinus, and are hurled in one 

 stream along the centre of the face, nearly to the project- 

 ing chin. Here is placed the orifice of the buccal funnel, 

 a perpendicularly descending tube of considerable width, 

 slightly funnel-shaped at the top, the interior surface of 

 which is strongly ciliated. It descends straight upon the 

 mastax, over the part where the unci unite. But just 

 above this point there are two valves projecting from the 

 walls of the tube, also well ciliated. These can be brought 

 into contact, or separated in various degrees, at will, and 

 being very sensitive, they regulate the force of the inflow- 

 ing current, and doubtless exclude hurtful or useless sub- 

 stances. The current now flows along the two rami of the 

 incus, as I have already described; and, passing between 

 their separated points, descends into the oesophagus, a 

 slender duct opening beneath them, and leading to the 

 digesting stomach. 



As this current passes, the manducatory apparatus acts 

 upon the particles of food which it brings in its course. 

 The quadrantic masses approach each other and recede, 

 with a rapid rolling movement, in the direction of the 

 curvature of the mallei; while, at the same time, the rami 

 of the incus open and close their points, rise and sink, 

 and occasionally perform a kind of shovelling action. The 



