212 



pt'lagic larva', is (|uilc willioul foiindalioii, lesliiig, no doubt, on niisintcr- 

 prolalions and l)c'inL!; 'Ii'^' I" most iinpi-rrcct niolliods of research. (The 

 staleinenl ol' tlie same author that these ()|)liiuii(ls also are lierniaphroditic 

 is equally phautastie, as 1 have shown in the papei- (pioted above). — As 

 loi- his slalenienl that in Opliialhiix I he iai\;e now develop into I he ly|)ieal 

 pluteus sJKipe, now develop throui*h a very imperfect larva, it rests on liie 

 researches of Apost elides^), who expressly says (()|). cil. p. 7()) that the 

 nine tenths of the larviv reared by him did not develop into the true larval 

 shajje but showed ' line forme plus ou moins arrondie, qui continm- a 

 vivre, el dans hupielle nous avons suivi le developpement coni|)let de 

 ranimal". Althoni>h he says to have ""des raisons d>' j)retendrt' <pie. jnscjira 

 la lin (In develop])eiiieid de I'animal, il eontinuera a en etre ainsi" it is 

 evident thai he has simjjly failed lo rear Ihe larva' beyond Ihe slage with 

 the posterolateral arms, the larva' dyini> when they had reached this 

 slai^e in fad, he slates himself that ■'cette forme singuliere ne conlinuera 

 plus a s'augmenler, mais pen a pen a se degrader, ju.squ'au moment de 

 sa disparition." 



While thus we need not trouble with this iinjierfect larva with only two 

 arms, the direct statement of Apostolides that he has followed the com- 

 plete (levelo])ment of the still simpler embryos cannot simply be done 

 away with, it does, however, seem very hard to believe il lo be correct 

 — and he does not give a single figure to accompany these remarkable 

 observations. That author moreover being anything but a first rate author- 

 ity it is impossible simply to endorse his statement. Il is a fact that 

 Giard's statement of these Ophiurids as being at times of the year vivi- 

 parous, rests on misunderstood observations: it is therefore hardlv too bold 

 lo suggest that .\postolidcs" statement likewise may rest on misappre- 

 hension. In any case, we cannot accept the statement, until it has been 

 confirmed by renewed researches by a com])etenl investigator. 



II would appear that Apostolides (Op. cil. p. 77) has also observed 

 those incomplete larval forms in the free. I would, however, suggest that 

 it may have been the rudimentary larval forms, Ophiopluleiis Mclschnikoffi 

 or 0. CAapavhlei, which he has observed. Hut that these larva^ should also 

 belong to Ophiolhrix, like the typical Ophiopluleiis, is exceedingly hard to 

 believe. The whole question, however, very iiiinli needs leinvestigation. 



As a further instance of poicilogony in Kchinoderms Giard mentions 

 Asterina and Aslerias. "Astcrina cephea habitant les mers chaudes, aban- 

 donneau hasard de la vie pelagique des oeufs (pii doivenl donner naissance 

 a des larves nageuses .... .1. yibbosa n'est done (luune forme poeciloge- 



') N. Aposlolides. Anotoniio ol dOvi'lopppinent fles Ophiurcs. Arcli. Zoo), rxpcr. & 

 g6n6r. X. 1881. 



