PART III.] 



Descriptive Anatomy of Bladder- Worm. 



495 



bottom, a little water is added so as to cover the object, and the whole placed on the 

 stage of a dissecting microscope. The bladder is slit open with fine scissors at the 

 part opposite to the orifice already referred to ; the membrane reflected from the 

 contents on all sides, and held down in this condition by means of fine pins inserted 

 into the underlying layer of cork (Fig 24). The inner surface of the membrane when 



Fig. 24. — The ruptured bladder spread out on a layer of cork by laeans of pins, with the coiled up parasite 

 adherent to its inner wall. Magnified about five times. 



thus spread out has been well discribed by Mr. Rainey, in the Philosophical Transac- 

 tions, as presenting the appearance of being sprinkled over with powdered glass. The 

 parasite, however, is not yet at liberty, but remains firmly rolled up, and if a needle 

 be gently drawn over the mass, it will be found that a perfectly even surface is 

 presented, and a hair passed into the original orifice in the bladder on the opposite 

 side (as here placed) will be found to press a layer of tissue before it ; in fact, the 



Fig. 25.— As Fig. 24, but the " receptaculum " split open, the rugse of the coiled up neck brought to view, as well 

 as the orifice by which the parasite eventually escapes. Magnified about 5 times. 



part touched by the needle and pushed forward by the hair consists of an exceedingly 

 delicate membrane (the " receptaculum ") enveloping the coiled up " neck." This, 

 again, may be laid open with a sharp dissecting knife, carefully reflected and held 

 down by the smallest pin obtainable (Fig. 25). The membrane in contact with the 



