958 



just sliown, rigor mortis is inlliicnred by llic central nervous 

 system along the autonomic nerve tracks, as is likewise the case 

 with the muscle-touus, 1 am of opinion that rigor mortis is a last 

 tonical muscle-shortening. This view is also entirely in keeping with 

 Pekelharing's ^) investigations, who proved that the percentage of 

 creatine of the muscles increases with rigor mortis, as is likewise 

 the case with increased tonus. 



Xow the question arises : how is rigor mortis brought about ? 

 Tlie usual explanation is, that through the mortitication of the cen- 

 tral nervous system the muscles receive stimulants along the nerve- 

 tracks, and these stimulants accelerate rigor mortis. P]wald was of 

 opinion that these stimulants originiite in the labvriuth, whilst 

 Fletcher proved that supply of oxygen makes the muscles mortify 

 without rigor mortis. I think lean now give a more general explana- 

 tion, corresponding with the facts that are known. 



We know that rigor mortis only begins, when the circulation of 

 the blood has ceased. We obtain then in all tissues an accumula- 

 tion of products of metabolism consequently suifocation. And 

 now it is known that, if we kill an animal by hemorrhage or 

 sufTocate it by pinching off the trachea, that then, by the influ- 

 ence of the autonomic nervous system, the body siiows manifold 

 irritation-situations: through tension of the arrcctores pilorum the 

 hairs stand erect in the dorsal skin-regions of the trunk and in the 

 tail ; the bladder empties itself and also the rectum. In an entirely 

 analogous way the sending of move |>owerful stimulants of the tonus 

 to the skeleton-muscles takes place. The stimulants running centri- 

 fugally, which during life-time entertain the muscle-tonus by means of 

 the thoracal autonomic nervous system, will now, at this increased 

 irrilabilify, after death cause a last powerful tonical shortening of 

 the muscles. 



When I had established in t!iis way, that the occurrence of rigor 

 mortis stands under the inlluence of the thoracal autonomic nervous 

 system the question rose, if, at least in fi-ogs, this influence, just 

 like the tonus, as P. il- Brondgeest -) has proved, is entertained 

 by stimulants produced along the posterior roots of the spinal cord. 



In this direction I made already 10 experiments. I cut the pos- 

 terior-roots 8, 9, and H) of a frog at one side. From the doctrine of 

 segmental anatomy we know, that these posterior roots contain the 

 sensitive nerve-tracts of the hind-leg. 



J) Ontlerzoekingoii van licL Physiolngii-cli Laboratorium to Utrodit .'xle R. XI 

 pag. I. 1910. 



~) P. Q. Brondgeest, Over c|pn tonus der willekeurige ppioron. Diss. Utrecht 1860. 



