288 THE ANATOMY OF CESTODES. 



was formerly of opinion that the analogue of the ordinary subcuticula 

 . was to be found in a " richly granular parenchymatous layer," dis- 

 covered by me under the cuticle. Although this layer has a peculiar 

 structure, and is but imperfectly marked off from the subjacent tissue, 

 my opinion was followed by subsequent observers, except Eindfleisch, 1 

 and the layer in question was even credited with a distinct cellular 

 structure. The most distinct description is furnished by Steudener, 

 who asserts that the subcuticular layer consists, in all Cestodes, of 

 extended, narrow, conical cells, which stand together like a palisade, 

 with the summits of the cones directed inwards, and with the bases 

 resting on the cuticle. Each cell has an oval nucleus, often slightly 

 broader than the cell itself, which, therefore, must bulge out at that 

 point. The nuclei lie in the middle of the cell, sometimes nearer the 

 summit, sometimes nearer the base, so that in a vertical section they 

 are not seen in a line, but irregularly alternating in a somewhat broad 

 zone. The two halves of these cells differ strikingly in their optical 

 and histological characters, for the basal portions are homogeneous, 

 while the other halves consist, according to Steudener, of a granular 

 protoplasm, in which the boundaries of the cells are but faintly dis- 

 tinguishable. 



An inspection of sufficiently thin and well-stained preparations 

 of Tcenia is quite enough definitely to prove that this sub-cuticular 

 layer is formed, not of mere granules, but of cells usually arranged 

 perpendicularly to the cuticle. It is not, however, so easy to accept 

 Steudener's reports as to the nature of these cells. I am unable to 

 resolve the finely granular outer layer into tops of individual cells, and 

 cannot therefore regard them as cylindrical cells. They seem to me 

 rather, as they formerly appeared to Eindfleisch and Schiefferdecker, 

 as spindle-shaped cells, whose protoplasm lies round about the oval 

 nucleus in a thin layer, and runs out at both ends into thin threads. 

 The outer ends lie against the cuticle, while the inner threads may be 

 followed some distance into the body-parenchyma, and, as I have often 

 observed, may come into distinct connection with the very fine trans- 

 verse muscular fibres. 



Nor can I recognise in these cells the matrix cells of the cuticle, 

 but agree with Eindfleisch in regarding them merely as peculiarly 

 formed connective tissue cells. I am further confirmed in this opinion, 

 since the cells in question sometimes lose their spindle form, and look 

 exactly like the connective tissue cells of the Cestodes. Thus it is, 

 for example, in the head of the tape-worms, in the parts connecting 

 the individual joints of Tcenia saginata (Fig. 147), and in the leaf-like 



1 "Zur Histologie der Cestoden," Archiv /. milcrosk. Anat., Bd. i., p. 140, 1865. 



