tape-woi;ms or the sud-family ayitellinix.t:. o.)7 



close to the cuticula of the suclcers, separated from the cuti- 

 cula by the superficial layer of muscles. This layer of cells 

 does not represent the subcuticula, but rather must be homo- 

 losrised with the " Sommer-Landois " cells of the subcuticular 

 muscles of other parts of the worm. The cells are more or 

 less flattened, and lie in a plane parallel to the cuticula — sub- 

 cuticular cells are perpendicular to the cuticular ; these cells 

 are multipolar (fig. 29), each cell sending- out several pro- 

 cesses, which either terminate in connection with nuiscle- 

 fibres, or connect with processes from similar adjacent cells. 

 The cells further stand in contact with the ganglion cells of 

 the sucker by means of nenro-fibrilla3 coming from the nerve- 

 cells. The nuclei of the neuro-muscular cells in the suckers 

 are oblong, small, measuring only 3'5ju long. The points of 

 resemblance between these cells and the "Sommer-Landois^' 

 cells are their connection with more than one muscle-fibre, 

 their niultipolarity, their connection with the central nervous 

 system (of the sucker in this case). 



Granted that these cells are reall}' the homologa of the 

 " Sommer-Landois " cells of the rest of the body, then the 

 muscles they belong to must be subcuticular muscles, as 

 "Sommer-Landois" cells have hitherto only been found con- 

 nected to subcuticular cells. 



The arrang'emeut of the muscles in the suckers follows 

 roughly the ariangement in the rest of the body ; subcuti- 

 cular muscles, in two layers, occupy the space directly under 

 the cuticula, and are parallel to the cuticula; parenchyma 

 muscles run perpendicular to the cuticula, and, in deeper 

 laj'ers, parallel to the cuticula. 



The suckers ai-e separated from the scolex by a delimiting 

 membrane; directly within this membrane are two sets of 

 fibres running parallel to it. The first set forms concentric 

 rins's, as can be seen on sections touching the base of the 

 sucker ; the second set radiates, the centre of the radiation 

 being at approximately the same spot as the innermost of the 

 concentric rings. These two sets lie close to each other, and 

 remind one of the subcuticular muscles, which they possibly 



