102 THE AMERICAN MONTHLY [May, 



sufficiently long to be examined. But they are very delicate creatures 

 and do not brook confinement long without drooping. The jar rec- 

 ommended to be employed is such as used by confectioners for their 

 sweets and fancy biscuits. In use it should be covered by a glass plate 

 to check evaporation as much as possible, and if one growing frond of 

 the green sea lettuce ( Ulva laiissima), attached to a clean stone, be 

 put into the water, sufficient oxj'gen will be evolved by its growth to 

 maintain the polyzoa in a tolerably healthy condition for some time. 

 The jar should be placed where light can fall upon it freely, but it must 

 not be exposed to direct sunlight, as the small bulk of water would be 

 heated thereby, and anything above the normal temperature is preju- 

 dicial to the polyps. A needful piece of accessory apparatus is a fine 

 muslin tow-net. It is made in the shape of a funnel, about one foot in 

 diameter at its wide end, and securely attached to a ring of brass wire 

 varnished with shellac; if an iron ring is used, it is apt to become 

 rusty. This net may be either towed after a boat as it is rowed along, 

 or it may be attached to a stick, and the surface of the water skimmed 

 from the side of the boat. The wash of the boat at its stern often scat- 

 ters those forms which had been attracted to the surface by the sun. 

 Whichever plan be adopted, the net must be occasionally raised and 

 drained, and then turned inside out in a pail of clean sea water, when 

 its contents will be washed ofi' ready for examinatioil. In examining 

 marine objects in sea water, always use a plate-glass stage, on the ordi- 

 nary stage of a microscope, to protect the brasswork from the conod- 

 ing action of sea salts. From pieces of glass cemented together securely 

 with marine glue, construct any special tank necessary for the exami- 

 nation of the polyps. Beautiful and dazzing as the polyps are in their 

 living actions, the student may desire to preserve the remembrance of 

 them in their dead forms, and to put them up for his cabinet. Various 

 plans have been suggested and tried. Thus some recommend a very 

 dilute solution of osmic acid ; this answers tolerably well, if most 

 gradually introduced into the trough while the tentacles are expanded. 

 It has, however, the drawback of slightly blackening the creatures. A 

 weak solution of bichloride of mercury, of about two parts of the 

 bichloride to one thousand parts of water, introduced in the same way, 

 has been successful in the hands of some mounters ; but the best re- 

 sults have been derived from the use of whiskey. A piece of glass 

 tubing has been melted over a spirit lamp, and drawn to a capillary 

 point ; this has been broken ofi', so as to leave a very minute opening 

 in it. If this tube be now filled with whiskey, and inserted by the 

 side of the trough holding the expanded polyps, the spirit will trickle 

 in very small drops down the side of the trough, and become so grad- 

 ually diftused through the sea water that the polyps, l^ecoming accus- 

 tomed to its blissful influence, succumb to it, and forget to draw in 

 their tentacles. In mounting these as permanent preparations, nothing 

 succeeds so well for a preservative fluid as glycerine and camphor 

 water, which answers for most marine objects. 



Among the many interesting objects to be examined at the sea-side 

 are those tiny shells known 2l% foratninifcra^ from the number of for- 

 amina which pierce their walls. They may be found in their living 

 state attached to marine algje, or in the oozy beds of a rock pool at the 

 lowest tides. It has been stated by some naturalists that they float on 



