98 THE CONNECTIVE TISSUES, BY A. ROLLETT. 



saline solutions. Dilute solutions of potash and soda, and also 

 of acetic acid, produce very similar effects. 



The experiments of Heidenhain* have shown that powerful 

 induction shocks cause contraction of the cartilage cells, render 

 them irregular in shape, and detach them altogether or in part 

 from the wall of the cavity. This was first observed by 

 Heidenhain in the cells of the cartilage of the head of tad- 

 poles, and in the articular cartilages of the adult frog. In the 

 former he also saw the molecular movement of granules pre- 

 viously visible in the cells effectually stopped. In shrivelled 

 cells there further occurred an accumulation of clear drops, or 

 similar drops were thrust out into the cavities of the cartilage. 

 The first action of the induction current is to produce a cloudi- 

 ness in the interior of the cells, which often suddenly traverses 

 them like a shadow. Heidenhain regards these phenomena 

 as the expression of commencing coagulation, as are also all 

 the changes induced by induction shocks, since he was unable 

 to observe that the death of the cells was accompanied by any 

 return to their original condition. 



If one of the above- described induction apparatuses be used 

 in order to apply a few opening shocks to the ensiform cartilage of 

 the Frog (Rana temporaria) covered with a covering glass, and 

 placed without addition of fluid upon tin-foil electrodes closely 

 connected with one another, it will be found that an entire 

 series of such shocks are always required to produce a distinctly 

 visible change in the cells, or a long period after the applica- 

 tion of a shock must elapse in order to allow the very slowly 

 following change to become apparent. The cells of the carti- 

 lage of Tritons behave themselves very differently in this 

 experiment. Here a single shock is sufficient to cause the cells 

 to contract rapidly, and even quite suddenly, under the eyes of 

 the observer, like transversely striated muscle when irritated ; 

 indeed, even the iron core may be removed from the primary 

 coil, and the secondary coil of the apparatus previously quite 

 thrust home may be withdrawn to considerable extent, and yet 

 the strength of current will still be sufficient to produce the 



* Studien des Physiologischen Instituts zu JBreslau, Heft 2. Leipzig, 1863, 

 1. 



