ÖFVERSIGT AF K. VETENSK.-AKAD. FÖRHANDLINGAR 189 4, N:0 8. 353 



effected by an acid being secerned from the operative cell. Re- 

 ferring to the wood-cuts it appears that the calcareous rod 

 gradually begins at some distance from the end to decrease in 

 width until it becomes fully constricted off, tlie isolated end- 

 piece being taken into the plasm of the operative cell in order 



Changes of form of one (two?) amoeboid cell engaged In dissolving the posterior end of a 

 calcareous rod of a mature pluteus. 1, an end piece of the rod already fully separated and 

 a second in the state of separation by constriction. 2 — 4, different views of the operative 

 cell up to the time when the first separated piece has become parted in two and almost 

 dissolved and the second piece has been detached from the main portion of the rod. 

 Drawn from a living pluteus. Highly magnified. 



1 was drawn at 9.20 a. m. 



2 10 a. m. 



3 10.35 a. m. 



4 11.30 a. m. 



there to be dissolved. Sometimes when the acid has exercised- 

 its dissolving influence for a short time on the rod, the 

 separating process is facilitated by the end-piece being simply 

 broken oflF; this is produced by the forcible movements of the 

 stomach, the wall of which is combined by fine plasmic threads 

 with the rod. 



