1 9 14] A New Cestode from A mi a Calva L. 87 



Musculature. 



The musculature consists of two series of fibres, namely, the muscles 

 of the parenchyma, coursing in three different directions, and those of 

 the cuticle, which are closely related through what will be described 

 below as the outer longitudinal group of the former. Since a careful 

 study of the miuscles was made, they will be dealt with somewhat in 

 detail, beginning with the simplest histologically, the dorso-ventral and 

 coronal fibres. Those of the scolex will be described separately. 



In his researches on Bothridiiim pithonis Blain. Roboz ('82) was 

 unable to find the myoblastic nuclei of the longitudinal muscles, which, 

 he says, are pointed at both ends, but observed a longitudinal fibrillar 

 striation. Zernecke ('95), working on several species, makes the follow- 

 ing statements concerning the individual muscle-fibres: "Hier finden wir 

 denn auch die von Salensky fiir die Muskeln von Amphilina beschrie- 

 bene Differenzirung der Fasern in eine centrale (Mark-) und eine 

 periphere (Rinden-) Schicht. Letztere umgiebt den centralen Theil 

 als ein breiter Ring und ist von diesem durch die intensive Farbung zu 

 unterscheiden. Sie ist von homogener Structur und starker licht- 

 brechend als das Centrum. Letzteres erscheint im Querschnitt als eine 

 dunklere, feinkornige plasmatische Markmasse"; further, "Hier (at 

 the level of the myoblastic nucleus) ist der Zusammenhang der Mark- 

 substanz mit der Zelle zu sehen. Die Rindenschicht bildet hier nicht 

 mehr ein geschlossenes Rohr um die Markmasse, sondern offnet sich an 

 einer Seite, so dass eine Rinne entsteht, durch welche das Plasma der 

 Bildungszelle mit dem Mark communicirt." Essentially the same 

 conditions were found in the musculature of this form, excepting that the 

 peripheral layers of the individual fibres of all of the different groups are 

 characterized by being broken up into a varying number of fibrils (Figs. 

 loa, b, c, and 9a) which diverge at the ends, excepting in the case of the 

 longitudinal fibres of the parenchyma. An example from the coronal 

 series (Fig. 9a) shows how the fibrils are related to the nucleus and 

 cytoplasm. Although in most of the fibres of the longitudinal muscles 

 the latter are situated close to the fibrils, as shown in Fig. 9d, others. 

 Fig. 9b and c, are widely separated from them, the connection being 

 scarcely visible in many cases. The two figures given are of the most 

 distinct examples that were seen. The fibrils themselves are very easy 

 to follow in every part of the strobila. In cross-sections of the external 

 longitudinal fibres at certain levels, a large area of highly-staining mater- 

 ial at one side of the fibre (Fig. loa and b) was considered to be the re- 

 mains of the nucleus, since no other trace of it was found. This and 

 the fact that the myoblastic nuclei of the dorso-ventral fibres between 

 the bothria were somewhat degenerate and quite closely related to the 



