ON A NEW CESTODE LARVA PARASITIC IN MAN. 15 



Some Points in the Structure of the Plerocercoid, — 



The cuticula, sometimes 8 /i thick but usually much thinner, 

 presents a homogeneous or finely granular appearance. In contact 

 with it is the delicate dermal musculature which as usual consists 

 of the external ring and the internal longitudinal fibers. As regards 

 the subcuticula and the general parenchyma there seem to exist 

 no points deserving special notice. 



The calcareous bodies {cal., figs. 17, 21, etc.), spherical or 

 ellipsoidal in shape and measuring 7i — 12 fx across, are abundantly 

 present in all parts of the parenchyma except in the anterior 

 body-parts. The head-end is always found to be free of them. 

 (In fig. 19 the numerous black dots stand for the calcareous 

 bodies.) Especially numerous are they in the bulky parts of the 

 larger specimens. It may happen that very small Plerocercoids, 

 such as seem to have been recently budded off, contain only quite 

 a limited number of them in the hind parts. In stained sections 

 the bodies appear sometimes pale and homogeneous, but more gen- 

 erally exhibit the usual concentric lamination ; they are either 

 stained or unstained. 



Quite remarkable is the occurrence, in the parenchyma, of 

 peculiar fat-like or yolk-sphere -like bodies of various sizes (r. n., 

 figs. 17, 19, 20, 22). They occur isolatedly or several together 

 in groups, without regularity as to their number and position in 

 the body. Sometimes they are numerously present and are often 

 of a considerable size, forming conspicuous objects when the 

 worms are observed under the microscope and giving the impres- 

 sion that they represent some internal organs (fig. 19). As a 

 rule they are constantly found in a greater or less number in the 



