358 W- S. NICKERSON. [Vol. XVII. 



granules which stain both with carmine and iron-haematoxylin, 

 though not intensely. The nuclei are small and lie at the 

 extreme basal ends of the cells. A condition which evidently 

 follows that just described is shown in PI. XXXIII, Fig. 19. 

 The form of the flask is retained, but the secretion has been 

 discharged, and the interior contains only the shriveled remains 

 of the gland cells. Several facts lead me to believe that the 

 whole organ soon afterward disappears. First, the observa- 

 tion that in some individuals the organs are entirely absent ; 

 and these individuals are frequently large, mature, actively 

 budding animals. Second, the presence or absence of flask 

 organs is not correlated with the sexual condition of the indi- 

 vidual. Third, animals having no flask organs have been 

 observed bearing buds on which flask organs were present. 

 Fourth, animals having immature flask organs have been ob- 

 served bearing buds on which flask organs, which appeared to 

 be fully developed, were present {cf. PI. XXXII, Fig. 11). Fifth, 

 mature individuals have been found with the flask organs pres- 

 ent on one side and wanting on the other, but showing no 

 indication that the missing organ had been lost through 

 mechanical injury. The only reasonable interpretation of these 

 facts seems to be that the organs arise from certain ectodermal 

 cells in the manner described, form and discharge a secretion, 

 and afterwards disappear. The fact that buds sometimes have 

 flask organs larger than those of the parent probably indicates 

 that the organs arise more than once in the life of the individ- 

 ual. The observed facts give no basis for determining more 

 definitely the function of these organs. 



It seems rather remarkable that no organs have been 

 described from other members of the genus Loxosoma which 

 appear capable of being homologized with these structures. 

 The only organs known to me which have been described for 

 other Endoprocta, and which appear in any respect comparable 

 with the flask organs of L. Davenporti, are certain structures 

 described by Ehlers ('90), p. 33, as occurring at intervals in the 

 stalk of Ascopodaria. Slight elevations of the cuticula, pierced 

 at the summit by a minute pore, cover little conical groups of 

 cells which differ in size and appearance from the surrounding 



