BY JAS. P. HILL. 35 



infolclings of the splanchnic epithelium, the spaces between these 

 infoldings being filled with blood and representing the glomerulus 

 vessels. For this view speaks the arrangement of the nuclei 

 which occur more or less regularly along the course of the vessels. 

 Round the nuclei an oval non-staining cell body can frequently 

 be recognised, and they can in some j^laces, as Spengel has 

 observed, pass directly over into the splanchnic epithelium. 



Efferent Proboscis Vessels : The efferent proboscis vessels after 

 they leave the glomerulus are essentially similar in their course 

 and disposition to those of Pt. minnta. However, as Koehler* has 

 found in Pt. sarniensis, the two efferent proboscis vessels are 

 connected with each other in the proboscis neck by a well-marked 

 vessel (figs. 10, 14, cv.) which passes, in the "chondroid tissue" 

 occupying the space between the anterior portion of the "keel" of 

 the proboscis skeleton and the posterior portion of the "end plate." 

 I have met this connecting vessel not only in transverse series, 

 l^ut also in both vertical and horizontal longitudinal series, and 

 there can, in my opinion, be no doubt as to its existence in this 

 species. Spengel, however, asserts that the efferent proboscis 

 vessels "never stand in connection with each other," and believes 

 "Koehler has been apparently deceived through the intense 

 colouration Avith carmine of certain parts of the skeleton which 

 thereby become very similar to the blood fluid."! A series of 

 transverse sections through an individual of the species under 

 consideration, whose vessels were richly filled with coagulated 

 blood, leaves me in no doubt on the matter, and the appearance 

 presented by the vessel as seen in tw^o adjacent sections is 

 represented in fig. 10 {cv.). The specimen was stained Avitli 

 cochineal in 70 % alcohol with the result that the coagulated Ijlood 

 stained a much deeper tint than the proboscis skeleton, allowing 

 the two to he very easily distinguished, and moreover the 

 coagulated blood in the connecting vessel could be distinctly seen 

 to pass over at both ends into that in the efferent proboscis 



* Contribution a 1' etude des Ent^ropneustes Internat. Monatsschrift 

 f. Anat. u. Histologie, Bd, iii. 1886, p. 174 



t hoc, cit, p. 633. 



