1 9 14] A New Cestode from A mi a Calva L. 85 



excretory canals forming the foramina secundaria which appear in 

 tangential sections as circular openings in a homogeneous matrix. Since 

 these course through the cuticle quite obliquely, they give the latter the 

 appearance of being pierced with holes at different levels. Two of them 

 are shown in Fig. 7, one having reached the outside while the other has 

 not yet passed the basement-membrane. 



In many cases a splitting of the outer layer of the cuticle into pro- 

 cesses takes place evidently along the lighter striations. It is quite con- 

 ceivable that the cuticular processes, if not "cilia", described for many 

 Bothriocephalids may arise in this manner in young scolices. 



The cuticle covering the scolex is, on the whole, somewhat thinner 

 than that on the posterior proglottides. This statement is also applicable 

 to that on the inside of the auricular appendages of the scolex and fore- 

 most joints. The other modification of the cuticle, referred to above, is 

 best seen in young scolices where the minute spines have not been worn 

 away. It will be seen, by reference to Fig. 8, that the latter are developed 

 as a thickening in the outer layer followed by a breaking up of the mater- 

 ial into stout spine-like processes. These minute spines are restricted 

 to a very narrow line running along the edge of the auricle, and are all 

 directed towards the inner concave surface of the latter, that is, towards 

 the central longitudinal axis of the worm. They gradually disappear 

 with the appendages posteriorly. Since these spines appear in great 

 numbers, and, since the appendages are provided with well-developed 

 sets of muscles (v.i.), obviously arranged to activate them, they must 

 be of actual service to the worm in obtaining a hold on the smooth mucous 

 lining of the host's intestine. 



SUBCUTICULA. 



The subcuticular cells (Fig. 7) are not clearly defined as to boundaries 

 but are fused together to form a syncitium the extent of which is in- 

 dicated chiefly by the nuclei. There are, however, condensations of 

 protoplasm around the latter in ripe proglottides, giving the appearance 

 of columnar cells which have been described for many Bothriocephalids. 

 These may even be more or less distinct towards the centre of the pro- 

 glottis, yet they are directly continuous with processes from the cells of 

 the parenchymatous tissue beneath, the whole forming in many places a 

 meshwork of protoplasmic strand surrounding vacuoles, as shown in the 

 left of the figure. The nuclei are comparatively large structures with 

 well-defined walls, non-uniform in thickness, and clear contents, except- 

 ing for the deeply-staining "nucleoli". The thickness of the subcuticula 

 varies in different regions, especially since its inner boundaries are rather 

 indefinite, averaging about 25M. Numerous processes proceed towards 



