L. Stieda on the Tsenise. 103 



group of small roundish corpuscles, measuring 0'035-0-056mill., 

 is formed ; these, gradually increasing in size and number, soon 

 occupy one-half of the joint. These corpuscles appear at first 

 finely granular, afterwards pale and transparent, and represent 

 the well-known testicular vesicles or testicular tubes of the 

 Tcenia. Transverse sections show that these testicular vesicles 

 are enclosed by a fine structureless membrane, and still contain 

 in the interior a cellular mass, whilst the fine, delicate, very long 

 seminal filaments already occur rolled up at the margin. Some- 

 times a fine efferent duct may be detected on these corpuscles. 

 At the same time, on the side of the joint opposite to the testis, 

 an elongated vesicle is formed from the aggregation of cells 

 there occurring; this is 0*210 mill, in length, and O'OvO mill, 

 in breadth at its widest part. This is the cirrus-pouch, which 

 is somewhat pointed at the extremity turned towards the median 

 line of the joint, and applies itself with the other (rounded) end 

 to the genital pore. It contains the penis or lemniscus, which 

 is 0'056 mill, in length, and 0014 mill, in breadth. This is 

 continued into the vas deferens, which disappears behind the 

 cirrus-pouch, without forming any loops. In favourable trans- 

 verse sections, however, it may be traced beyond the median 

 line of the joint. I have never seen any connexion between it 

 and the above- described fine efferent ducts of the testes. 



In the following joints (80-100), whilst the testicular vesicles 

 and cirrus-pouch still further increase in size, the female organs 

 also make their appearance. While previously there was only 

 an indistinctly limited organ of undefined appearance between 

 the testes and cirrus-pouch, we may now distinguish two organs 

 distinctly separated from each other in form and contents. At 

 the lower margin of each joint there is an elliptical body, with 

 its longest axis placed in the transverse diameter of the joint ; 

 this is the germ-stock, which measures 0-0280-0-0350 mill, in 

 length, and 0*210 mill, in breadth, and appears to be filled with 

 finely granular contents. Below, the germ-stock is pretty 

 sharply defined; but above, its limits are not so distinctly marked, 

 because the yelk-stocks are situated upon it. The latter occupy 

 the space between the germ-stock and the upper margin of the 

 joint, spreading out right and left ; they appear as if composed 

 of a number of larger and smaller caeca, which seem to unite at 

 the median line of the joint. Their contents (as may be seen 

 by tearing them to pieces, and still more distinctly in transverse 

 sections) are coarsely granular, consisting of a quantity of very 

 small, homogeneous, strongly refractive corpuscles. At the 

 lower margin of the cirrus-pouch there is a more or less distinctly 

 projecting canal, which is somewhat dilated at its orifice in the 

 genital pore. This canal, which is 0021 mill, in diameter at its 



