238 THE MALE GENERATIVE ORGANS 



narrow circular tube within the hard coating of the zoon. I use 

 the expression, " hard coating of the zoon," because its power of 

 resistance to disintegrating influences is very great. It is only 

 amenable to liquor potass^ after long maceration, but its behav- 

 iour in the digestive organs of other aquatic animals is interest- 

 ing. I fed young newts with C. miniita and C. ctnerea, and after 

 a few days' feeding I killed the newts and extracted the viscera. 

 The shelly substance of some of the Cypris was unaffected, but 

 those which were near the rectum were soft and pulpy and the 

 viscera partially digested, but the spermatheca was intact and the 

 spermatozoa active. In other newts that I fed, some of the 

 Cypris were enabled to resist the gastric juices that are poured 

 into the alimentary canal and to pass, /(?/• anum, alive. I have 

 taken them out of the rectum of a newt, placed them in water in 

 a watch-glass, and they have been none the worse for their Jonah- 

 like experience. For four days I fed some Sticklebacks with C. 

 viinuta, and on the fourth day I opened them to see results. The 

 greater number of the Cypris were lying in the intestine, dead 

 but undigested. Those which were in the oesophagus, when 

 placed in water, recovered their vitality. I examined some of the 

 dead specimens. The spermatheca was intact, but the sperma- 

 tozoa, as a body, had lost their mobility, except in one case, 

 which was close to the pylorus. They had preserved their vitality, 

 although the Cypris was dead. I also found one specimen of 

 Cypris, whose viscera had been entirely absorbed, leaving the 

 spermatheca, filled with spermatozoa, intact in the interior of the 

 valves. The valves were in a very pulpy condition. These I 

 mounted in glycerine (Fig. ii), to show the density of their 

 structure and capability of resisting the absorbing and disintegrat- 

 ing influence of the gastric juices. 



Cypris Minuta (Brady), Figs. 9 and 10.— In adding a draw- 

 ing of the bursa-copulatrix and second foot of C. viimtta, I do so 

 because Brady frankly admits that he has never seen a perfect 

 specimen of the male of this creature. This is, I presume, 

 because it is somewhat rare in English ponds. I found it to be 

 very plentiful in a low-lying pond in this district, which is full in 

 the winter, but quite dry in the summer (from the month o^ 

 October last year to January of this year), after which time I 



