PERIVISCERAL FLUID OF ECHINODERMS. 249 



III. SUMMARY. 



From a comparative study of the cellular elements in the peri- 

 \Nceral fluid of a repre-ent.:- jroup of Echinoderms found in 

 the vicinity of the Puget Sound Biological Station the following 

 conclusions have lu-cn reached: 



1. The leucocyte- are < on-tant in the peri\ isceral fluid of the 

 I ' liinodrnn-. 



2. Tin; li-in - in all of the 1 .< him idrnii- >tudied are phago- 

 cytic and thromboblastic and in -< ! ippear to be sclero- 

 Ha-iic and a-soeialed \\ith nieill of re-ectrd -ke'.etal 



IS. 



; v llcni' IN with IH-IIK^I..!.!!! . are found only in cer- 



of the I liilnihuniidi-a and ted with the de\ rlo])- 



iiirnt of a highly mu-t ular 1><1\ . 



4. Modilii alion> ol tin- 1'icalhin^ organs ha\t- a] ] lan-nt ly no 



"ii llu- cellular (fntci, be 1 ! i\ Nn-ral fluid, so that 



no spi-( ih. 'It-M-lopi-d in tho-i- forms 



with a rigid noii-nniM. ular 1><1\ \\all dr.-pitr the limitations of the 



breathing 



5. < >f tllr ".HlKll with S|ilnTlll< ~, " tlloM- \\itll Cololi' 



s|)lu-i ulr- an- pu---iit in tla- Ophiu: I .1 hinoidra and Holo- 



tlmroidra and arc prrdoininaiit in the l.i-t 1 "Amn-liocyti-> 



uiih red -phi-ri. ' in tin- 1 '.< hiiioidra, whrre the 



>i/e .Mid numlu-r pie-ent i.- correlated with the depth of color of 

 the body \\all. 



6. YiluMtile corpu>rle- are pn-ent in the Ophiuroidea, I'.rhi- 



noidca and in >'//</. <>n;itn* "alone of the Hnlothumidra 



studied. In the latter -; he\" are pi^nieiited and are re- 



led as i-lN \\hich function a- do the hemocyir- in other 

 mu-cular-liodied 1 Joint humid' 



A. KN)\\I I DGM] NFS. 



I \\i-h to take thN op]mrt unit\" to e\|>re m\ - thank> to the 

 Ohio Aiadeim of Seieiiee for a re-e.irch grant which aided me in 

 carrying on thi> in\ < -i i^ation. 



Awerinzew, S. 



'ii (jber die pigmente von S. droba Arch. Z. EXJH.T.. \'III: i \iii. 



Bush, M. 



'21 Rrxisni Key to the Echinoderms of Friday Harbor. Publ. Pu.yt >!. Biol. 

 tii'ii. Ill: 65-78. 



