Fluke Parasitic in the Go])per-heacl Snake. 41 



which is most frequented. They seemed to ordinary 

 inspection quite black, and as many of them were at least a 

 quarter of an inch in length, there was no difficulty in 

 seeing the oral and ventral suckers. 



Habits. — As the specimens were numerous and all alive, 

 I had plenty of opportunities of observing their habits. 

 They were seen to move along in the interior of the semi- 

 transparent stomach at a comparatively rapid rate, by 

 extending the body its full length, then iixing the head 

 sucker and contracting to the fullest extent. In this way a 

 continuous progressive movement was kept up. The same 

 movement was seen on placing them in a little water in a 

 watch glass, from which they tried to escape, and the amount 

 of alternate expansion and contraction displayed was 

 considerable. They also sometimes moved to and fro in the 

 water. Usually when taken from the body and placed in a 

 little water, or water and glycerine, they discharged the 

 dark-brown ova in successive jerks sufficient to discolour the 

 water or mixture. Almost invariably when taken direct 

 from the bod}^ and placed in water on a slide under the 

 microscope, they were observed to jerk out the ova with 

 considerable force, from an opening adjacent to, and 

 immediately behind the oral sucker. In its force and 

 suddenness, the discharge seemed like a display of fireworks. 

 In some instances, the brown ova were so completely ejected, 

 as to render the body white-looking to the naked eye, while 

 in others only a veiy partial discharge took place. It is 

 very instructive to observe the eggs passing out of the body 

 in Indian file, and this can be done leisurely. I placed a 

 specimen on a slide, and a cover-glass over it, so that when 

 gently pressed, a constant stream of ova flowed out, quicker 

 or slower, according to the pressure, and as long as desired. 



The ova discharged so near the mouth orifice would 

 frequently fill it, then they would be sucked in and suddenly 

 thrown out and scattered in all directions. Another 

 movement frequently observed under the microscope, was 

 that of apparent feeding. Every now and again, what 

 seemed a long neck-like portion of the body would be 

 stretched forward and the mouth opened at the same time, 

 then the body would contract and the mouth-opening close. 



They assumed all sorts of shapes and proportions in 

 moving to and fro, well seen as they moved about on a 

 moistened slide. In water they could remain alive for some 

 time, for several hours at least. 



