54 



one of the slates suspended by means of wire from strips 

 extending across the top of the box from one side to the 

 other. It seemed to me, however, that there was little 

 doubt but that the sino'le vouno; oyster found on the slate 

 seventeen days after the spawn had been put into the 

 box, was one of the embryos which had been so intro- 

 duced. The flannel, like the cotton, becomes befouled 

 in a few days with a muddy deposit held together \\dth 

 a disagreeable slimy material : it, like cotton and bolting 

 cloth, rots in a couple of weeks so as to be easily torn by 

 fishes and other water animals, such as musk-rats. Once 

 the enclosure has been invaded by a larger animal forcing 

 its way through the tlannel, as happened in the case of 

 the large box. one can no longer be certain that embryos 

 naturally fertilized in the open waters may not have 

 found their Avay in. The experiment with the large box 

 was useful however, as showing that eujbryo ascidians 

 and barnacles might be pretty etf ectually excluded by the 

 use of textile membranes through which the water had 

 to be strained before it could enter the box. 



PROPOSED XEW METHODS OE CARIXa EOR ARTIEICIALLY 



IMPREGXATED EGOS. 



From this season s experience it results that I have but 

 little faith in floating boxes or enclosures of any kind in 

 which cloth is used to keep the eggs or embryos confined. 

 Few cloths are evenly and closely enough woven, if they 

 could be kept clean, to retain in an enclosure eggs as 

 small as the l-oOO of an inch in diameter, which is about 

 the size of those of the oyster, clam, shiij-worm and per- 

 haps many more marine animals of various types, such 

 as erabryulogists would be glad to study, provided they 

 had an apparatus which would enable them to work con- 

 tinuously. 



Finding that ^vliai we wanted was a device which 

 would enable the operator to change the water on the 

 embryos and eggs continuously and at the same time not 



