POLYSTOMATOUS CONDITION OY CORDYLOPHORA. 23 



On a PoLYSTOMATOus Condition of the Hydranths of 

 CoRDYLOPHORA LAcusTRis. By HuGH Price, Demy of 

 Magdalen College, Oxford. 



Specimens of the beautiful hydroid polyp Cordylophora 

 were brought by me last summer from the Victoria Docks for 

 the use of the class of practical zoology at University College, 

 London. Professor Kay Lankester drcAV my attention to 

 certain abnormal-looking hydranths amongst these specimens 

 "which appeared to possess a number of supernumerary oral 

 cones. I isolated some of these abnormal specimens and 

 made them the subject of further study. 



It should be stated that these observations were made at 

 the end of June, 1875, on specimens which had apparently 

 already produced their crop of gonophores, and consisted 

 almost entirely of nutrient hydranths which were develop- 

 ing with some vigour, as evidenced by the clean and pale 

 flesh-coloured appearance of their supporting stalks. I 

 presume that a crop of gonophores had been already pro- 

 duced by these specimens, since others obtained from the 

 same locality Avere in full sexual maturity. An outline 

 sketch of two of the polystomatous hydranths is given in 

 Pigs. 1 and 2, where o c indicate the oral cones. Pig. 1 

 is a pentastomate, fig. 2 a tristomate hydranth, each cone 

 having an oral aperture at its apex. The oral cones are 

 larger in the latter than in the former, and are seen to 

 present scattered tentacles on their surfaces, in addition to 

 those which are present on the common body uniting the 

 three cones. 



The questions which presented themselves for solution in 

 connection with this hitherto unrecorded mode of growth 

 in Cordylophora were — 1. Is such a production of super- 

 numerary oral cones a normal phenomenon in this genus ? 

 2. Do the cones proceed to develop into complete hydranths 

 and become divaricated by the production of interposed 

 hydrocaulin? or do they become detached as fissiparous 

 buds ? or does the monstrous condition maintain itself per- 

 manently ? 3. Have the supernumerary cones developed in 

 consequence of an injury to the parent hydranth ? or were 

 they indicated already in the earliest condition of the 

 hydranth which bears them ? 



These questions I have not been able satisfactorily to 

 resolve, but think it desirable nevertheless to place the facts 

 observed on record as well as some observations on arti- 

 ficially produced polystomatous hydranths of Cordylophora, 



