PLATE 1 



EXPLANATION OF FIGURES 



1 Silver suprapubic tube with flange wliich was sewed into the bladder. 



2 Silver piston with cap which was screwed into the suprapubic tube when 

 the experiment was not being performed. 



3 Piston encased in flanged tube. 



4 Cap of piston exposed, in situ, on the ventral abdominal wall of the four 

 weeks-old puppy. 



5 X-ray of the suprapubic tube and piston, in situ, ventral view. 



6 X-ray of the suprapubic tube and piston,. in situ, lateral view. 



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