54 
spaces left by fat now extracted by alcohol and real nutritive va- 
cuoles, agree with the observations that I have made on living 
intestinal cells in other Cotylean Polyclads. Minot’s granular giand 
cells are totally absent in the intestinal coeca. Therefore the pre- 
parations make it very probable that the function of Minot’s granular 
secretion is to transfer the nutriment in such a condition that it 
can easily be distributed to the coeca, where it is finally assimi- 
lated through intracellular absorption. Thus the main gut in this 
case takes the part of a stomach; i. e. a spacious receptacle for the 
initial preparation of the food pumped in by the pharynx. After 
disaggregation the food can then be delivered to the diverticula 
for intracellular digestion. I might here only mention that Westblad 
(1922) takes another standpoint in the case of Minot’s giand cells. 
As in Prosthiostomum, there are numerous intestinal branches 
from the sides of the main gut. No anastomosis has been ob- 
served in the lateral parts of the body. 
A remarkably short, but wide, unpaired intestinal branch arises 
from the anterior end of the main gut, and is slightly inserted 
over the pharyngeal pocket, where it very soon ends blindly (Plate 
II a, Pig. 4, ia). This is the very rudimentary, insignificant remnant 
of the common, unpaired anterior intestinal branch of the Polyclads. 
Such a branch occurs fully developed in Prosthiostomum. The 
degeneration in the case of Euprosthiostomum is due to the faet 
that the wide pharyngeal pocket has appropriated all the Space 
available inside the muscular wall of the body. 
When thus the ru:imentary anterior unpaired intestinal branch 
does not continue over the pharyngeal pocket, one would not ex- 
pect to find any intestinal diverticula running over the brain. How- 
ever, in Euprosthiostomum a very narrow median intestinal branch 
occurs. It arises from a transversj anastomosis between the most 
anterior pair of intestinal coeca immediately in front of the pha¬ 
ryngeal pocket. This then compensates for the reduction of that 
part of the normal unpaired intestinal branch that lies over the 
pharyngeal pocket. Consequently, the more anterior section of the 
unpaired median intestinal diverticle, which is after all the one 
important for the supply of nutriment and oxygen to the brain, 
still remains. 
Genital organs: The ovaries lie as usually dorsally, the 
