Ihc following accounts do not pretend to display any fa lly new 



the science; their object is only to widen in some points our present views in n g 

 to the activity of the amoebocytes, especially respecting their ability to arrange them- 

 selves into plasmodia or network, and, furthermore, to complete my former nol 

 their mode of operation when absorbing and destroying the larval skeleton. 



In 1879- 1880 Geddes- published an interesting paper on the ; ral 



fluid of the sea-urchin, giving detailed information in regard to the different corpus 

 immersed in it. Considering that previous to him distinguished in such as 



Valentin, Williams, Hoffmann, and others have busied themselves in studying the 

 same matter, and seeing, moreover, that recently several other investigators, al 

 all Prouho 3 and Cuénot ' have been occupied with studies on the perivisceral and 

 ambulacral fluids in the echinoids, it would appear rather superfluous to search into 

 this matter in order to get anything new out of it. Indeed I am not able to add any 

 new information in regard to the corpuscles in question as they really are when 

 moving in the fluid of an animal quite unhurt, but their mode of operation, their ten- 

 dency to fuse in order to form plasmodia and network, and their structure when in- 

 fluenced by conditions more or less different from the normal, appear to have b 

 somewhat disregarded and therefore in want of further explanation. It is from this 

 point of view alone, that I intend to treat the subject, and that mainly by giving 

 tolerably true views of some of the various configurations which the are 



able to form and of the structure of their protoplasm. 



My researches are performed on the coelomic fluid of Echinus esculentus and 

 miliaris. If the perivisceral fluid is taken from an animal just captured and is brought 

 to a standstill in a glass, it is known to undergo remarkable changes and 



1 Öfversigt af Kongl. Vetenskaps-Akademiens Förhandlingar. 18 



2 Archives de Zoologie expérimentale, vol. S. \<y. (83 — 494. pis 37—38. 



3 Archives de Zoologie expérimentale, (2) vol. 5. 18 j .-95 — 310. pi. 19. 



4 Archives de Zoologie expérimentale. (2) vol. 9. 1S91. 1 641. pi. 18. 



Festskrift för Lilljrborg. 



