17G 



OESOPHAGOSTOMA COLUMBIANUM, Curtice. 

 Platk XXV. 



Fig. 1. Worm in third 8tage, x60: a, head, witli chitinous armature; h, (i'w»i»h:igiia ; 

 c, intestine; (Z, unicellular glauds ; e,auus; /, liuedenotiug natural leiif;tl). 



Fig. 2. Cephalic eud, lateral view, Xl50 : a, chitiuous cup ; b, one of the six cephalic 

 papilla', (these are slightly distorted) ; v, side view of the neck-fold, under 

 which the gland-ducts d, d, open on the ventral line ; e, tesoi)hagiis ; /, 

 intestine. 



Fig. 3. Worm in lirst stage when 0.23""". long. No internal organs were seen in 

 this specimen. 



Fig. 4. Cephalic end, ventral view : a, head ; h, neck-fold, near, which are the neck 

 papillj© g, O'y c, ojsophagus; d, d, unicellular glaud.s, whicli open under the 

 fold h; e, intestine; /,/, glands. 



Fig. 5. Worm inclosed in its cyat. 



Fig. C. Tumor from which the cyst in Fig. 5 was taken : a, surrounding tissue dis- 

 sected from caicum ; h, fluid-tilled space ; c, capsule with inclosed worm. 



Fig. 7. Older tumor. This differs from tumor of P^'ig. (>, in having a movable cheesy 

 mass. These tumors are distorted by compression, which makes them too 

 flat. Figs. 6 and 7, and Fig. 3, Plate XXVI, present three stages in the dis- 

 ease, as seen in fresh tissues under low magnifying powers. 



Fig. 8. Section of an advanced tumor: a, mucous membrane ; h, submucous; c, inner 

 muscular layer; d, outer: e, serous membrane; /, the cheesy mass of the 

 tumor in which is a small section of the worm. This presents a more ad- 

 vanced stage of the disease than Fig. 2, Plate XXVI. 



