128 



W. C. CURTIS. 



the condition of the female organs in the proglottids thus ob- 

 served. There are four main water vascular tubes. The larger 

 pair lie on the same side of the body as the uterus opening and 

 in the majority of cases one or both of them can be traced to a 

 bulb-like enlargement on either side near the anterior tip of the 

 proglottid. Posteriorly each one seems to end in the angle of 

 the broadly wedge-shaped concavity formed by the projecting 

 flaps. They here seem to end blindly against the cuticle which is 

 perhaps perforated. There is no cross connection between these 

 two vessels nor any common posterior opening such as is fre- 

 quently stated to occur in Tcenias. The second pair of main 

 trunks are vessels of much smaller diameter and lie on the other 

 side of the flat body immediately under the larger pair. Ante- 

 riorly they can sometimes be traced a little farther forward than 

 the bulbs of the larger vessels, but do not seem to end in an en- 

 largement. It is almost impossible to follow these smaller trunks 

 for any distance posterior to the penis as the yolk glands are 

 here closely packed together and obscure everything else. 



FIG. 2. Ripe motile proglottid fully extended, showing full uterus and the larger 

 pair of water vascular trunks. 



When the proglottids are examined alive much of their struc- 

 ture is obscured through the presence in the parenchyma of the 

 highly refractive and closely packed granules of calcium carbon- 

 ate. A very easy way of ridding the proglottid of this and pre- 

 paring it for immediate examination is to use ten per cent, nitric 

 acid and the pressure of a cover-glass. This dissolves the cal- 

 cium carbonate and leaves the specimen quite transparent. This 

 is a valuable method for the rapid examination of the principal 

 organs, but for the finer details one of course needs more careful 

 fixation and a good stain. I have found corrosive sublimate 

 with about five per cent, acetic acid followed by Czokor's alum 

 cochineal an excellent combination for the demonstration of the 

 features given below. 



