BARNACLE GEESE— GOOSE BARNACLES. 119 



It is unnecessary for me to describe more minutely the 

 anatomy of the Cirripedes ; I have said enough to show 



of the top with sea-water, and place it in any shaded part of a room — 

 not in front of a window. Put in the pan six or eight pebbles or clean 

 shells of equal height, say i d or 2 inches, and on them lay a clean 

 sheet of glass, which, by resting on the pebbles, is brought to within 

 about 25 inches of the surface of the water. Select some limpets or 

 mussels having acorn-barnacles on them ; carefully cut out the limpet 

 or mussel, and clean nicely the interior of the shell ; then place a 

 dozen or more of these shells on the sheet of glass, and the barnacles 

 upon them will be within convenient reach of any observation with 

 a magnifying glass. If this be done in the month of March, the ex- 

 perimenter will not have to wait long before he sees young Balani 

 ejected from the summits of some of the shells. Up to the moment of 

 their birth each of them is inclosed in a little cocoon or case, in shape 

 like a canary-seed, and most of them are tossed into the world whilst 

 still enclosed in this. In a few seconds this casing is ruptured longi- 

 tudinally, apparently by the struggles of its inmate, which escapes at 

 one end, like a butterfly emerging from its chrysalis, and swims freely 

 to the surface of the water, leaving the split cocoon or case at the 

 bottom of the pan. Some few of the young barnacles seem to be 

 freed from the cocoon before, or at the moment of, extrusion. From 

 three to a dozen or more of these escape with each protrusion of the 

 cirri of the parent, and as the parturient barnacle will put forth its 

 feathery casting net at least twenty times in a minute for an hour or 

 more, it follows that as many as ten thousand young ones may be pro- 

 duced in an hour. These, as they are cast forth at each pulsation of 

 the parent's cirri, fall upon the clean sheet of glass, and may be taken 

 up in a pipette, and placed under a microscope, or removed to a 

 smaller vessel of sea-water, for minute and separate investigation. It 

 seems strange that animals which, like the oyster and the barnacles, 

 are condemned in their mature condition to lead so sedentary a life, 

 should in the earlier stages of their existence swim freely and Aerrily 

 through the water — young fellows seeking a home, and when they 

 have found it, although their connubial life must be a very tame one, 

 setthng down, and not caring to rove about any more for the remainder 

 of their days. These young Balani dart about like so many water- 

 fleas, and yet, after a few days of freedom, they become fixed and im- 

 movable, the inhabitants of the pyramidal shells which grow in such 

 abundance on other shells, stones, and old wood. 



