5TSKRIFT FÖR LILLJEBORG 



Summary, 

 i The white amoeboid corpuscles in the Echinoids always tend to communicate 



and fuse together. 



1 1 'hen the Echinoid is quite unhurt, the corpuscles are prevented from doing 



by the currents caused by the ciliary movements. 



3. / / 'hen brought to a place unaffected by the currents thus left to their own 

 limited motive power, the corpuscles intercommunicate and fuse in order to form a net- 



k and plasmodia. 



4. The corpuscles cannot move by their own power to such still places devoid 

 of cilia, but they are drifted there by the encircling currents. 



5. /// the Echinoids an opportunity is afforded to investigate under the micro- 

 \pe the transformation of wandering cells into a "tissue", which, when fixed and 



stained, bears a certain resemblance to reticular tissues in vertebrates. 



6. There exists only a gradual distinction between network and plasmodia, 

 the former being brought about by the union of the pseudopodia, the latter by the fusion 

 of the cell-bodies themselves. 



7. The plasmodia closely remind one of the large, multi-nucleated masses 

 termed Ostoclasts, Myeloplaxcs, or even giant-cells met with under pathological conditions, 

 but they originate in quite a different way from what is supposed to be the case with 

 the Ostoclasts. 



8. The formation of the above mentioned plasmodia and network in the Echi- 

 noids may, strictly speaking, not be looked at as pathological; if the contrary, most of the 

 interesting results previously obtained by investigations of the leucocytes or phagocytes 

 must, for the same reason, be considered peculiar to pathological phenomena. An 



/.•inö/d having a small piece of the shell broken, or concealing a small cover-slip in 

 its body cavity, does certainly not suffer from any essential disorder. 



In my "Notes on the Formation and Absorption of the Skeleton in the Echi- 

 I wrote: 



"When a cell begins to exercise its absorbent influence on a calcareous body, 

 for instance a spicule, it strains to extend and flow round and over it so as to take 

 it whole into its protoplasm, and hence the granular main portion of the cell moves 



tly, .^li'lim; slowly along the swallowed spicule until nothing remains of it. 

 During this process the pseudopodia are continuously withdrawn and given out again, 



Vetenskaps-Akademiens Forhandlingar. [894. N:o 8. Stockholm, p. 351. 



