Physiology. — "A Contribution to the pathological histology of 

 striated muscle-tissue". By P. Nieuwenhuijse. (Coinmunicated 

 by Prof. C. A. Pekelharing). 



(Communicated in the meeting of December 29, 1917). 



During my stay on the isle of Urk as medical officer I found 

 in the dorsal muscles of a plaice a rather big hard white knob, 

 which consisted of striated muscle tissue and looked like a tumour. 



At the microscopical examination I was struck with the peculiar 

 changes of the muscle fibres which were quite unknown to me, and 

 which in the beginning I considered as belonging perhaps specifically- 

 to muscles of a fish. 



When however later on I found that similar changes also occur 

 in human muscles, it became evident that we had to do in this 

 case with a process of more universal significance, which can 

 appear in striated muscles in general. 



Macroscopical examination: A plaice (Pleuronectus platessa), caught in the 

 North-sea, long 31 cm. showed at the right upper side of its body an irregular 

 hard knob nearly as big as a child's fist which was prominent under the unda- 

 maged skin. 



In sections it appeared that this knob consisted of muscle tissue, rather hard of 

 consistence, pale coloured with yellow spots here and there and sharply marked 

 against the surrounding tissue. 



The knob could in some places easily be detached from the surrounding muscle 

 tissue, so that it reminded us in many respects of a fibromyoma in the musculature 

 of the uterus and consequently looked quite like a tumour. 



The knob consisted principally of two parts, separated by connective tissue, which 

 diverged in the proximal direction and so in some sections they made the impres- 

 sion of two single knobs (Fig. 1). 



The plaice was for the rest normal and well nourished; neither in the other 

 muscles nor in the internal organs any abnormities could be stated. 



Microscopical : The pieces were fixed in formalin (10 ^/q) imbedded in paratfin 

 or celloidin and stained in different ways. Some pieces were before imbedding 

 hardened in Müller's solution; after that a number of frozen sections were made 

 and finally by means of teased preparations I tried to isolate some fibres. 



In the preparations we could see that the knob consisted only of striated muscle 

 tissue, the fibres of which, showing many signs of degeneration, were of diffe- 

 rent size. 



