PLASMODIA OF ^THALIUM iii 



As is well known, the endoplasm of Amcebse contains, for 

 the most part, numerous granular contents of very various 

 sizes. Whenever I was successful in making out clearly the 

 position of these granules in the meshwork of the proto- 

 plasm, I always found them deposited in the network itself, 

 never, on the contrary, in the clear contents of the meshes. 

 The granules constantly show an undulating, almost a 

 dancing movement, frequently reminding one in the latter 

 case of molecular movements. This proves in any case that 

 the internal protoplasm is relatively very fluid. At all 

 events the framework is in a state of continual undulating 

 movement. 



Mihaliivm septkum {Fuligo varians) ^ 



It was only after the manuscript of the present work was sent 

 off that I found an opportunity of investigating the protoplasm of 

 yEthalium, an object of so great and so long a recognised import- 

 ance for the study of living substance. I must regret that I 

 had not already paid before a closer attention to this organism, 

 for, as regards the protoplasm question, it is one of the most 

 instructive with which I am acquainted. Hence, it seems 

 justifiable to make in this place a brief supplementary report 

 as to some observations on the protoplasm of this Myxomycete. 



Unfortunately, I have only as yet made a cursory study of 

 the living protoplasm, but I shall try, as soon as possible, to 

 make up for this deficiency. The protoplasm, fixed in the way 

 described above, with the picro-sulphuric-osmic mixture, shows 

 the alveolar structiu'e more distinctly and beautifully than do 

 the majority of the objects described before. This is partly 

 connected with the fact that it is very easy to obtain plasmodia 

 of j^thalium in so thin a layer that they vie with the thinnest 

 sections. Now, since the processes of manipulation that are 

 performed in embedding and cutting do not in any way render 

 the structures more but rather less distinct (as I convinced 

 myself in JEthalium, of which I also made sections), it is obvious 



1 These observations on tlie protoplasm of j^thalium and Pelomyxa were 

 made by the author after the text of this work had been finished and sent to the 

 press. In the original German edition they were placed in an Appendix at 

 the end of the work, but in the present edition these, as well as other 

 additions of the Appendix, have been inserted in the text in their proper 

 places. 



