52 



ones of such a small kind of shell-fish. But by comparing them with the figures 

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

 Or perhaps they are young of the animal defended by a testaceous covering like 

 a little shell-fish, which at the time of its maturity separates from its umbilical 



cord from whence it drops and soon adheres to a proper substance as a 



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

 here also another peculiar view regarding the ocecia 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 Cellaria avicularis) 

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

 plants.* 



Lamouroux' also mentions the ocecia in B. neritina, and introduces us to 

 several hypotheses regarding the functions of these formations. »0n les a con- 

 siderees comme des opercules que le polype construit a volonte, soit pour se 

 mettre a I'abri du choc des corps exterieurs, soit pour hiverner, soit encore pour 

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

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

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

 quelque-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 fois qu'elle existe, les ovaires sont vides. 



Milne Edwards^ considers the ocecia in Eschara as well as the avicularia 

 on the zocecia as »vesicules gemmiferes«, or »capsules gemmiferes«. »Les obser- 

 vations de Loefling et de plusieurs autres naturalistes nous ont appris que ces 

 vesicules (ooecia) sont des capsules gemmifferes, et par consequent nous sommes 

 porte a croire qu'il doit en etre de meme ici, et que le tubercule pyriforme, dont 

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

 consid^re comme etant un receptacle contenant les gemmules et servant a leur 

 livrer passage. 



Lamarck^ also uses the name »vesiculse gemmifer3e«, but just as often the 

 name »ovaria« for the ooecia as well as for the gonothecse in the hydroid polyps. 

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

 (Cellaria) possess such formations, is repeated here: »Vesiculse gemmiferse nuUse, 

 nisi bullae qvse in nonnuUis speciebus extant «. 



Reid^ studied living specimens of Biigula avicularia with eggs in the ooecia. 



52, p. 1,S3— 134; '^ 77, p. 48; ' 51, p. 174; ■" 95. 



