PERIVISCERAL FLUID OF ECHIXODERMS. 243 



Echinoidea alone, those containing yellow >pherules in the Echi- 

 noidea and some of the Holothuroidea, and those containing color- 

 less spherule- in the Ophiuroidea, Echinoidea and Holothuroidea. 

 In the Echinoidea, the "amoeb' with red spherules" were 



numerous and largest (12 micnm- in diameter) in S.francis- 

 (Fig. 2~>\ in S. drobochiensis i Fig. 26) they were 



numerou- and -mailer (9 microns in dian In } : ..hinarach- 



jiin ley wt less numerous and -mailer 



[0 mi< rons in diamei.-r . The pnd< miinant type of pigmented 



ani"i te in / -'.ricns wa- the type with yellow -pherulc- 



,!]d the-e wnv ji M licularly mas-ed on the peritoneum 



(if the inte-tine. S d yell' mentcd amcel \ If- \\ ere 



ol,-.T\.-d in ,< but ii" . iatioii with .\ 



t-m \\a- not- 



Tl:<- K"| puincnt in the pi^meiiird amoebocytCS of tlie lu 

 noide.i \\a- de-i^nati-il c. hii n- by M.Miinn (.'t^.SL The 



\ ii-w .f tin- author and < .ninth- I '.^7 < that the amcebocytes >n- 



t. lining ( hinnchi-iii' ! with u transportation 



ha- lle\T been fill! pled. ( Uellot ('gib Wa- the lir-t t 



(,j-p..-e thifl a nmjitioi) .uid Stated that there was n.. change in 

 the depth "! the ( 'lor when the cell- Were allowed to -land ill the 



air, and that the contained pigment instead of being an oxygen- 



Carryinj d -up food material which the (ell- had 



taken from the inte-tine. Further, \Vinter-tein -Imwed that a 

 -olutioii of ecliin.ichrome doc- !) up more >\\ -en th.m the 



-anie amount of -i-a\\ater. Tlii- a--ertion of \\inter-tein'- i~ 



liticaut. because it open- up tl . -tion a- to the ,,\\ 



ie(iuirenient- ot the I'diinodi-rin-. Of course ii i- ol >\ i..u- that 

 all of the free OXJ gen u-ed by the l ; . hiiioderm- i- taken from the 

 Beawatei and further it ha- been -hown that except for a ililler- 

 etice in albuminoid content the periviMvral tluid of the l : .chino- 

 derms i- the .-a me den-it\ a- the -ea water a'tieiiot . ')!). There- 

 fore. \\e can a nine that there i- a dilfu-ioii of the si-.iwater 

 through the breathing organ- of the Fcliinoderm- and that the 

 oxygen c..ntent i- the >ame in the peri\i-ceral tluid .1- it is in the 

 out.-ide seawater. \Yith tht 'tioii of certain of the Holo- 



thuaiide.i. all of the Fcliinoderm- ha\e a very slight develop- 

 ment of rapidly contractile muscle elements and hence no need 

 fora large amount of oxygen for muscular activity, from which it 



