402 T. B. ROSSETER ON THE ANATOMY OF 



the rostellum, like the inverted linger of a glove, leaving a circular 

 orifice at its proximal end. Not that the rostellum is cylindrical 

 or tubular, as was supposed by Dujardin (following Rudolphi, 

 who says "Rostellum cylindricum "), in the case of T. ahiuosa 

 and T. trilineata * ; but the external cuticle folds inwards in 

 the act of inversion. There are four strong muscular suckers 

 placed equidistantly round the subglobose scolex. 



The neck is short and narrow. It varies in different specimens, 

 and segmentation commences quite perceptibly a short distance 

 from the scolex. 



In a mature worm which, like the one under consideration, 

 had shed its uterine proglottides, the " anlage " or commencing 

 formation of the reproductive organs does not occur until 

 the 182-200th segment from the scolex is reached, or about 

 5'737 mm. down the strobila, and where the segments hav^e a 

 mean width of 0*304 mm. The proglottides elongate themselves 

 proportionally as the organs of generation develop. The usual 

 sequence of development common to the Taenidae is pursued, and 

 a gradual wasting of the genital organs ensues when the act of 

 coition has taken place and the receptaculum filled with sperm. 

 The act of fructification usually takes place when the 300th 

 segment is reached, or about 22*413 mm. from the scolex. The 

 act of absorption is slow, and at the point where my specimen 

 broke off — viz. the 400th segment — the proximal testes still 

 existed, but in an attenuated form ; and the afferent and efferent 

 ducts had been entirely absorbed. 



Description of the Genital Organs. 



The genital cloaca is situated on the dextro-lateral margin of 

 the proglottis near its posterior end. It is an elongated narrow 

 cavity, and forms one of the lateral serrations. The -genital pores 

 are unilateral, and although distinct from each other, are enclosed 

 in one matrix. 



il- (f 



Histoire des Helminthes," pp. 573-574. 



