A certain interest is attached to those forms that have led to the establishment of a distinct species:—
Cysticercus acanthotrias, Weinld., 1858.
In making the autopsy of a white Virginian woman who had died of phthisis, a cysticercus was found in the dura mater, and eleven or twelve specimens in the muscles and subcutaneous tissue. Weinland and Leuckart, who examined the specimens, found that they resembled Cysticercus cellulosæ in form and size, but that they carried on the rostellum a triple crown, each consisting of fourteen to sixteen hooks, which differed from the hooks of C. cellulosæ or of Tænia solium by the greater length of the posterior root process and the more slender form of the hooks; the large hooks measured 0·153 to 0·196 mm., the medium-sized hooks, 0·114 to 0·14 mm., and the small ones 0·063 to 0·07 mm.
On account of these differences a distinct species of cysticercus was established, and this naturally presupposed a corresponding species of Tænia (T. acanthotrias, Lkt.); this could be done with justice so long as the case remained isolated, i.e., in America, as there was the possibility of the corresponding Tænia being found. In this respect, however, the position has changed; Delore first described a cysticercus the size of a nut from the biceps muscle of the arm of a silk-worker in Lyons; according to Bertolis this specimen possessed hooks of three different sizes, the dimensions of which corresponded with the figures given by Weinland and Leuckart; the correctness of the diagnosis could hardly be doubted, as Bertolis was known to be a very exact observer. A second case has become known through Cobbold, who regards a specimen of a cysticercus in Dallinger’s collection as likewise belonging to Cysticercus acanthotrias; this specimen also came from a man’s brain; finally a third case, also from France, has been published by Redon. This author, amongst numerous C. cellulosæ of a man, found one that had forty-one hooks in three rows, and he was the first to express the opinion that C. acanthotrias does not represent a distinct species, but is only an abnormality of C. cellulosæ. This view was also taken by Blanchard and Railliet, and is probably correct, as the discovery of the large corresponding Tænia furnished with three rows of hooks is not to be expected in European beasts of prey, and in Redon’s case C. acanthotrias as well as C. cellulosæ occurred simultaneously.
The duration of life of C. cellulosæ in man is very long; cysticerci of the eye have been known to persist for twenty years, and in cysticercus of the brain ten to nineteen years may elapse from the first appearance of cerebral symptoms until death. Dead cysticerci may shrivel up or become calcified, perhaps also undergo fatty degeneration and then absorption. Finally, it may be mentioned that if particular proof is required that C. cellulosæ of man belongs to the cycle of development of the Tænia solium, such proof has been furnished by Redon.
Note.—Tænia tenella, mentioned on p. [332], was ascribed by Cobbold to cysticerci of the muscular system of sheep. It has, however, been demonstrated that these cysticerci belong to the cycle of development of Tænia marginata (dog) (Cysticercus tenuicollis, from the omentum of sheep); but as already stated C. cellulosæ also occurs in sheep. Chatin himself swallowed the cysticercus, which Cobbold termed C. ovis, without causing a Tænia to develop in his intestine. Müller also vainly sought to induce infection with C. tenuicollis in his own person. On the other hand, the feeding of a dog with Cysticercus ovis resulted in the production of Tænia marginata.
Tænia bremneri, Stephens, 1908.
Characterized by the large size of the gravid segments. The largest was 32 by 9 mm. Smallest 21 by 6 mm. Average 28·6 by 8·5 mm. Mode 21 by 6 mm. Uterine branches twenty-two to twenty-four in number. Calcareous bodies numerous, 15·2 µ in diameter. Eggs maximum 45·6 µ by 41·8 µ. Smallest 34·2 µ by 30·4 µ. Mode 38 µ by 30·4 µ.
Tænia marginata, Batsch, 1786.
Syn.: T. e. Cysticerco tenuicolli, Küchenmeister, 1853.