Cysticercus //o^i a rar«^ l>vli>liin. 4Jl 



formiuo; i\ aliallow cup. At the anterior end of each 

 botliiiiliiini there is a .sinall roiuideil iiiuscuhir "accessory 

 sucker" (ti<^. W, S.). 'J'ho apex of the scoh>x hears a slifjht 

 papilla ("inyzorhynchus") (fig. 3, P.), hut there are no 

 hooks of any kind. The scolex measures ahout 0*5 mm. in 

 leni;tli and ahout 0*2.") mm. in width at the level of the 

 accessory suckers, 'i'lie hothridia, including the accessory 

 suckers, are ahout 0*3 mm. long, the diameter of the accessory 

 suckers themselves heing 0*1 mm. The neck, in a woll- 

 advanced specimen, measures 0'2 mm. in thickness and is of 

 very nearly the same diameter throughout its length, though 

 slightly widened here and there. 



The histological structure of the animal presents some 

 features of interest. The wall of the external " hiadder," as 

 has heen mentioned, is greatly thickened, especially on two 

 o|)posite sides. Tlie groundwork ot this thick envelope con- 

 sists of loose parenchymatous tissue, with a few scattered 

 muscle-fihres. There is a slight concentration of these 

 towards the periphery, as seen in tiansverse sections, forming 

 a vague circular hwer. Externally the surface is coveretl 

 with a delicate cuticJe, immediately helow which there is a 

 thin coat of circular muscle-fihres, followed again by a thin 

 coat of longitudinal muscles. 



The parencliyme is densely crowded with calcareous bodies, 

 showing the usual concentric structure. In addition to these 

 there are immense numbers of fat-cells, each enclosing a 

 large globule of fat. This fat is so abundant that it at first 

 hindered the preparation of satisfactory serial sections, as io 

 was found that a layer of it, partially dissolved out of the 

 tissues by the xylol used in the process, was formed round 

 the object when embedded in paraffin in the usual way. 

 This difficulty was found to he easily overcome by a short 

 immersion in ether before clearing. The fat-cells were very 

 beautifully deniojistrated by staining thin shavings of the 

 parencliyme with SiuiaJi Til. and mounting in glycerine. 



The parencliyme of the bladder-wall also contains numerous 

 branclung excretory vessels with delicate walls. These 

 enipty eventually into a wide and siifUous excretory canal, 

 o|)ening to the exterior by a minute pore at the posterior end 

 of the bladder. This pore is, in some cases, just visihle to 

 the naked eye. 



The structure of the long " neck " shows the same lavers 

 as have been described for the bladder, but in the reverse 

 order, and tluy may be seen to pass over from one to the 

 Ann. & Ma<j. N. Hist. Ser. 9. Vol. iii. 28 



