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Zoology. - "On the structure of the nerve-cells in the central 

 nervous system of Branchiostoma lanceolatum." (First comra.) 

 By I))-. .1. Boeke. (Communicated bj Prof. G. C. J. Vosmaer). 



(Communicated in the meeting of April- 26, 1907). 



The methods of staining the elements of the nervous system, 

 published in recent years by Ramon v Ca.ial, Donaggio, and especially 

 by Bielschowsky, have enabled us to study the minute structure ot 

 the ganglion-cells not only of the lower animals but also of the 

 vertebrates with more success than before. After having published 

 in These Proceedings, some years ago '), the results of my former 

 investigations on the structure of the nerve-cells of Branchiostoma, 

 then studied by means of the goldmethod of Apathy, it seemed ad- 

 visable to describe here too the results of my recent investigations 

 on the same subject by means of the methods mentioned above, 

 because they extend and complete my former results in several 

 directions. 



Contradictory to the results of Edingkr '\ the only author who 

 studied the central nervous system of amphioxus by means of the 

 method of Bielschowsky, viz. that the method gave only scanty 

 results for the neurofibrillae in the cells, in my preparations, stained 

 after the method of Bielschowsky — Pollack, in a great number of 

 nerve-cells of several specimens of Branchiostoma a very clear and 

 distinct picture was obtained of the neurofibrillae, not only in the 

 nerve-fibres, but also in the body of the nerve-cells. 



Preparations of material preserved in a mixture of platinum chloride- 

 osinic acid-acetic acid and corrosive sublimate '), and stained in thin 

 sections with iron-haematoxylin after Heidenhaix, were used as control 

 and for the study of the protoplasmic structures between the neuro- 

 fibrillae. 



The different cell-forms of the central nervous system gave there, 

 where they were satisfactorily stained, as a rule the same mode of 

 arrangement of the neurofibrillae in the cell-body: therefore I will 

 restrict myself to describe here only some cell-forms at length and 

 only refer briefly to the structure of other cells. At another place 

 I hope soon to give more and fuller details. 



!) Proceedings Roy. Akad. of Sc. Amsterdam, of the meeting of Oct. 25, 1902. 



2) Anal. Anzeiger, Bd. 28, No. 17, 18, 24 April 1905. 



3 ) According to Dr. Legros the best method for the preservation of the nervous 

 system of Branchiostoma. 1 can fully agree with him in this statement. This 

 mixture gives better results than all the others 1 tried. 



