398 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
stomach is a gelatinous rod, the Crystalline Style (fig. 36). 
In dissections it seems to fill the whole lumen of the 
alimentary canal at this point, though belonging, as 
pointed out, to the one compartment, for microscopic 
sections are necessary to see the separating ridges. 
Pecten shows a primitive condition in that the style lies 
in the intestine, but other forms are known connecting 
this with the complete separation of a crystalline style sac, 
appended to the stomach. There has been a great amount 
of discussion with regard to the origin and function of the 
crystalline style, almost every writer formulating a new 
theory, one or two of which will be considered here. The 
style has been regarded:—(1) As playing a part in the 
act of generation (von Heide, Cailliaud); (2) as a 
rudiment of the radular sac of the Glossophora (Balfour) ; 
(3) as acting mechanically upon the food under the action 
of the digestive fluids (Milne Edwards), or serving to bring 
the food particles between the style and the dense cilia of 
the epithelium (Sabatier); (4) as preventing the food 
from passing too quickly through the alimentary canal 
before it has time to digest (Kellogg); (5) as a reserve 
food material (Hazay, Haseloff; (24 and 25); (6) as an 
excretion (Claus); (7) as lubricating the undigested food 
particles passing through the intestine (Barrois) (28); 
(8) as an active digestive ferment (Mitra) (26). 
In Pecten maaimus the style is large, sometimes 
attaining a length of three inches. It is circular in 
transverse section, and widest near the stomach into 
which it protrudes. From here it tapers to a point near 
the end of the descending limb of the intestine. The 
upper end is sometimes rounded and enlarged, forming a 
knob; at other times it is connected with the gelatinous 
lining of the stomach, and it seems certain that this 
‘fleche tricuspide” and the crystalline style are 
