270 H. J. VAN CLEAVE 



made the statement " Wahrscheinlich stehen diese Zellen mit 

 einem, hier vorhandenen Tastvermogen in Beziehung." Saeffti- 

 gen ('84) thought this condition in E. clavaeceps resulted from the 

 four retractors of the proboscis forming a space between them 

 and in this the nuclei had come to he. 



Hamann ('91, p. 51) has shown that in the ontogeny of E. pro- 

 teus a group of three cells is laid down at the anterior end of the 

 proboscis early in development. *'An der Spitze sind auf dem 

 Schnitt drei der grossen Kerne mit ihrem kugeligen Kernkorper- 

 chen getroffen, deren Zellsubstanz den centralen Teil der Riissel- 

 anlage bildet," He has found such cells in all species of Echi- 

 norhynchus which he has investigated. As to their location and 

 relations he adds ('91, p. 57) : '^Bei Echinorhynchus proteus und 

 angustatus liegen sie nebeneinander, bei Ech. clavaeceps hinter- 

 einander .... Seine Abbildungen lassen das Verhaltnis 

 dieser Zellen zur Haut (Subcuticula) nicht deutlich erkennen." 

 Hamann considers the evidence insufficient to warrant the naming 

 of this structure an alimentary tract. On the other hand he has 

 offered the suggestion that the staining reaction of this tissue in 

 E. clavaeceps is such that the granular structure with hematoxy- 

 lin staining indicates a glandular function. For this reason he 

 called the cells gland-cells. I do not consider the evidence suffi- 

 cient to warrant ascribing a definite glandular function to this 

 structure, but since there does not seem to be any close relationship 

 between it and the other organs, might it not be the vestige of 

 some organ which through disuse has degenerated since the Acan- 

 thocephala have acquired the parasitic habit? 



Eorhynchus gracihsentis. This terminal organ of the proboscis 

 in Eo. gracihsentis (fig. 6). contains three large oval nuclei lying 

 in its long axis. It will be recalled that this arrangement of the 

 nuclei is what Hamann ('91, p. 57) has described for Eo. rutili. 

 The relative position of these is apparently influenced by the state 

 of contraction of the proboscis muscles. In case the proboscis is 

 fully extended these nuclei assume a regular oval form, the long 

 axis of each coinciding with the long axis of the body, but in various 

 stages of contraction of the proboscis these nuclei become slightly 

 modified in their relations. When forced closer together, they, at 

 times, come to lie with their long axes at right angles to the main 



