52 



ones of .such ;i small kind of slicll-lish. Hut l>y c-ouipaiing tluMii willi liic figures 

 of others of this genus, they appear rather to he what we have called Ovaries. 

 Or pcvhaps they arc young of the animal dclcnded by a testaceous covering like 

 a little shcU-lish, which at tiic time of its maturity separates from its umbilical 



cord IVom whence it drops and soon adheres to a pro])er substance as a 



base, beginning to form a Coralline like the parent animal.- There is discussed 

 here also another peculiar view regarding the oa'cia and the avicularia, both 

 having been considered as nectaries: »A later writer, who is a strong advocate 

 for the vegetation of Zoophytes, supposes these little pearl-like figures as also 

 those like the heads of birds in the Birds-head (Coralline (or OUaria avicularis) 

 to be their Nectariums, analogous to what is so called in the flowers of some 

 plants." 



Lamouroux' also mentions the oa-cia in li. neritiiui, and introduces us to 

 several hypotheses regarding the functions of these formations. On les a con- 

 siderees comme des opercules que le polype construit a voionte, soil pour se 

 metlre a I'abri du choc des corps exterieurs, soil i)our liiverner, soit encore pour 

 fermer sa demeure lorsqu'il a cessc de vivre. II est probable qu'aucune de ces 

 hypotheses n'approche de la verite, et je pense que ce sent des ovaires renfermant 

 les germes de nouveaux individus; j'ai observe (jue ces corps vesiculaires sont 

 quekjue-fois tres-entiers, et dans ce cas je les ai toujours vus remplis de petits 

 corps globuleux; il parait que ces ovaires s'ouvrent par une fente transversale; 

 toutes les Ibis i|u'elle existe, les ovaires sont vides. 



Milne Edwards- considers tlie oa'cia in F.schdid as well as the avicularia 

 on the zooecia as "vesicules gemnnferes«, or »capsules gemniiferes«. »Les obser- 

 vations de Loefling et de i)lusieurs autres naluralistes nous out a|)|)ris cpie ces 

 vesicules (ofpcia) sont des capsules gemmiferes, el par eonseepient nous sommes 

 porte a croire (|uil doit en etre de meme ici, et que le tubercule pyrifornie, dont 

 nous venous de decrire les divers etats (the avicularia in E. sulcata) doit etre 

 considere comme elant un receijlacle conlenant les gemmules et servant a leui- 

 livrer passage. 



Lamarck' also uses the name »vesicula' gemmilei;e , but just as oflcn the 

 name ovaria for the oa^cia as well as for the gonothecie in the hydroid |)olyps. 

 The same doubt, which Pallas had, as to whether the free, plant-like forms 

 (Cellaria) possess such formations, is repeated here: '>Vesicula; gemmiferu' nulla', 

 nisi bullic qv;e in nonnullis speciebus extant. 



lieid' studied living specimens of BiujiiUi (iniciildria with eggs in the oti'cia. 



' .'I'j. p. l.-ili— 134; -■ 77, p. 48: ' .'.1. ji. 174: ' <).->. 



