The family Koellikeriadae. 149 



cular film supplied with the arterial blood of the host thioiigh the 

 cord described and drained by the vein of the sanie cord. This 

 arrangement is almost like the vascular stroma of a tumor or like 

 the circulation supplied to the foetus inasmuch as it evidently maiu- 

 tains the nourishment of the parasite. 



The ovoid worms measured 24 X 28 X 40 m. There were in all 

 five of them although one was reduced to a hardened brown shrunken 

 mass which proved later to contain many recognisable eggs although 

 the rest of the body was shrunken into a sort of niummified form. 

 Otherwise they were all alike in form. Whether they lay two in 

 a cyst or alone cannot be stated with certainty. On attempting to 

 make out something of the structure of the animal it was found 

 almost impossible to avoid tearing the fragile skin which formed 

 the smooth outer surface and thus allowing the segments to pull 

 apart. However, as will appear, these segments are not all of the 

 same size and are not all continuously connected in the inferior 

 of the worm. Instead the vascular membrane entering between 

 them at one point spreads out from the middle to lie in crevices 

 among them in every possible direction. Any section of the mass 

 shows these Spaces containing a filmy connective tissue carrying the 

 blood capillaries of the host. 



At about that central point one niay discover, by separating 

 the segments, a small pointed white teat-like projection not more 

 than 5 mm in length which proves to be the head. Ordinarily it 

 is quite hidden down among the voluminous masses [of the body, 

 and whether it can Stretch out so as to appear outside the sphere 

 is difficult to say. 



Little conld be made out of the structure of the worm except 

 by means of serial sections since the tissues were so excessively 

 delicate and at the least touch ruptured to flood everything with 

 eggs which appeared like yellow paint, so fine and so adherent 

 they are. 



A whole worm was embedded in celloidin and cut into thick 

 serial sections which gave the topography of the internal organs. 

 From another thin sections were made in various situations and the 

 head was separated and cut into serial sections. From all these it 

 was determined that the following conditions exist: 



The pointed head and neck measure 5 X 14 mm and therefore do 

 not form an elongated filiform structure such as has been described 

 in other forms. At the base this neck spreads out into the lobu- 



