296 THE ANATOMY OF CESTODES. 



but the same must be said of the " plasmatic longitudinal vessels," 

 described by Sommer and Landois, and referred by them to the ali- 

 mentary system. 1 Similarly Botticher described the cephalic ganglion 

 of Bothriocephalus latus as an anastomosis of excretory vessels, 2 and 

 I have myself regarded the lateral nerves of B. cordatus as of a 

 vascular nature. 3 



Schneider was the first to identify these structures as nerves, 

 and observed a wide anastomosis formed by them in the head of 

 Ligula and Tcenia perfoliata. His identification was not based so 

 much on their liistological structure as upon their anatomical resem- 

 blance to the nervous system of Nemertines. The resemblance in- 

 cludes among other points this, that in both Tcenia perfoliata and the 

 Nemertines the nerve cords are lined with cells towards their ventral 

 and dorsal surfaces. SchiefFerdecker has supported Schneider's con- 

 clusion, trusting mainly to the results of a histological investigation, 

 according to which the so-called " vessels " are resolved into spongy 

 tracts, consisting of fibrils with layers of very delicate fragile cells. 

 Schiefferdecker believes further that he has found peripheral nerve 

 endings, both on the muscular fibres, where they have the form of the 

 so-called "terminal triangles," and also as independent structures, 

 something like Pacinian bodies (O011-0'017 mm. long by 0'004-0-006 

 mm. broad) distributed through the body-parenchyma of T. solium, 

 T. clliptica, and especially abundant between the thick fibrous bundles 

 of the musculi transversales. 



The almost contemporaneous researches of Blumberg* and Steu- 

 dener, and the essentially corroboratory results of my pupil Kahane, 

 with which my own observations lead me to concur, may be held as 



decisive as to the presence and general 

 nature of the nervous system. 6 



The cephalic ganglionic mass con- 

 sists of a tolerably thick transverse 

 band, which in Tcenia lies somewhat 

 deep below the proboscis or so-called 



FIG. 152. Nervous system of Tcenia " rOStellum," but which in BothriO- 



perfoliata. (x 20.) cephalus and Tetrarhynchus is some- 



what approximated to the upper surface of the head. The ends of 



1 In Tcenia these strands were erroneously described as simple canals, and as lying in 

 the inside of the excretory vessels ; Zeitxchr. f. uriss. Zool., Bd. xxiv., p. 515, note, 1874 ; 

 see Nitsche, ibid., Bd. xxiii., p. 191, 1873. 



2 Archivf. pathol. Ansit., Bd. xxx., p. 109, 1864. 



3 First German edition of this work, Bd. i., p. 445. 



4 " Ein Beitrag zur Anatomic der Taenia plicata, T. perfoliata und T. mamillana," 

 Archivf. wits. u. pract. Tkierheilk., Bd. i., p. 23, 1877. 



5 [See also the later investigations of Pintner, " Untersuchungen iiber den Ban des 

 Bamlwurmkorpers," pp. 67, et seq. : Wien, 1880. R. L.] 



