ABSTRACT
Obvious as are the ovicells and partially-developed ova of the cheilostome Polyzoa, the precise position of their ovaria and testis has not yet been determined ; the general idea that the ova are developed within the ovicells being wholly an assumption. The investigation of the question is not without difficulty, on account of the delicacy of the ova in their young condition, the greater or less opacity of the ectocyst, and the obstruction offered by the other viscera if the cells be viewed in any of the positions which they ordinarily assume, lying, that is, on their front or back faces. By tearing up a polyzoarium, with needles, into single series of cells, and causing one of these series to lie upon its side, I found the process of examination much facilitated.
