An Aid in the Study of Nematocysts. 



239 



of the solution takes place. The pressure which is thus produced is trans- 

 mitted to the receiver, and, as in the case of the model described above, 

 causes the sides of the flexible tube to collapse together. As the pressure 

 increases, the wall of the tube, at the point where the free and the attached 

 portions join, becomes folded into the interior of the carrier, the process 

 continuing until the tube, turned inside out, is extended upwards and 

 opens freely into the funnel. 



M< 



Fig. 3. 

 Apparatus for Osmotic Experiment. 



Fig. 4. 



Apparatus for Simplified Osmotic 



Experiment. 



The tension of the nematocyst is readily illustrated in this experiment by 

 corking the upper end of the glass carrier, the effect of which, besides 

 preventing the eversion of the tube, is still further to distend the dialysers. 



The above experiment can be considerably simplified by delivering the 

 flexible tube directly into the dialyser (Fig. 4). In order, however, that the 

 process of eversion may be seen, the carrier is first telescoped into a wider 

 glass tube which in turn is fitted into the rubber cork of the dialyser. The 

 funnel is in this case unnecessary, provided that the carrier is made long 

 enough to hold the flexible tube, when it is fully extended. 



