NEMATODES 261 



MULLER, A. Beitr. z. Kenntn., d. T. echin. (Munch, med. Wochenschr., 1893, 



No. 13.) 



PEIPER. Verbr. d. Ech.-Krankh. in Vorpommern., Stuttg., 1894. 

 WIEDEMANN, C. Z. Statist, d. Ech.-Krankh. in Vorp. In.-Diss., Greifswald, 1895. 

 SCHMIDT, W. Ueb. d. geogr. Verbr. d. Ech. mult. u. hyd. i. Bayern. In.-Diss., 



Miinchen, 1899. 

 RIEMANN, H. Ueb. d. Keimzerstr. d. Ech. im. Periton. (Beitr. zur klin. Chir., 



xxiv ; also In.-Diss., Rostock, 1899.) 



TSCHOTSCHEL, K. Zur Cas. d. Ech.-Krankh. in Vorp. (In.-Diss., Greifsw., 1900.) 

 POSSELT, A. D. Geogr. d, Verbr. Blasenwurmleid., insb. d. Alveolarechin.Tl. Leber 



seit, 1886. Stuttg., 1890. 

 MELNIKOW-RASWEDENKOW, N. Studien iib. d. Echin. alveol. s. multil. (Beitr. z. 



path. An. u. allg. Path. [Zeigler], Suppl. iv., January. 1901.) 



ADDENDUM. 



Tcenia hominis, v. Lstw., 1902. 



Scolex measures 1*34 mm. in length, 2 mm. in breadth. There is 

 a rudimentary rostellum without hooks on the apex ; the suckers 

 are deep ; behind them there is a ring-shaped swelling ; no 

 pigment. The neck is rn mm. in breadth. Calcareous bodies 

 very numerous, 0*013 nun. in size. Genitalia ? Only one immature 

 specimen has come to our knowledge, which was found in 

 Aschabad by Anger (C. f. Tcenia asiatica, p. 233), (v. Linstow in 

 C. f.. B., P. u. I., 1902 [I-], xxxi., p. 770). 



C. NEMATODES, Thread-worms. 



Nematodes are as a rule elongated round worms of a filiform or fusi- 

 form shape ; their length varies according to the species from about i mm. 

 to 40-80 cm. The outer surface of the body is smooth or annulated, and 

 at certain points provided with papillae, occasionally also with bristles and 

 alar appendices. The anterior end carrying the oral aperture is usually rather 

 slender, occasionally quite thin ; the posterior end is pointed or rounded ; 

 the anus, as a rule, lies somewhat in front of the posterior extremity. 

 The sexes are almost always separate, and the male can as a rule be 

 easily distinguished from the female because the former is smaller and more 

 slender, its posterior extremity is often spiral or incurvated, or carries an 

 alar appendix, whereas the female is larger and thicker, and its posterior 

 extremity is straight. In the male the genitalia open into the anus ; the 

 sexual orifice of the female opens ventrally along the median ridge in the 

 anterior half of the body, in the middle, or a Little further back. Both 

 sexes, moreover, have an orifice, the excretory pore, which is situated ventrally 

 along the median ridge and fairly near the anterior extremity. 



In large species, even with the naked eye, two lighter transparent 

 stripes the lateral ridges may be distinguished ; they run along the sides 

 of the body from the anterior to the posterior end, while two other stripes } 

 the median ridges, running along the ventral and dorsal median ridges are 

 less evident ; in exceptional cases there are also four sub-median ridges. 



