154 HOW TO WORK 



the shells, and then drop one or more alga bearing shells into each 

 beaker according to its size ; in a short time the sides of the jars, 

 especially the sides turned towards the light become coated with 

 spores; the sides turned from the light I keep clean with a chisel- 

 shaped piece of wood and a knob of sponge, so that whilst one half 

 of each jar is covered with a green oxygen yielding coat, the other 

 half is free for observing the animals that may now be placed in the 

 beakers. Behind this protecting coat, red algae will be found to 

 thrive. In this way a number of aquaria may be speedily provided 

 for our collections that will keep healthy for months, with the slightest 

 amount of attention. 



After the sides are properly covered with spores, the sea-weeds 

 should be removed and the jars placed on a table at such a 

 distance from the window that the light impinges only on the coated 

 half, taking care, however, that there is sufficient to stimulate the 

 spores to throw off bubbles of oxygen daily. If on leaving a place I 

 wish to take any specimens away with me, I pack these beakers con- 

 taining them in a rough box, of a size suited to the number selected, 

 with seaweed between the interstices and at the latest moment tie 

 bladder over each jar, which I remove at the earliest opportunity 

 after arriving at my destination." 



Prawns, fish, actinias, &c., may be fed on shreds of beef, which has 

 been pounded and dried, and then macerated in sea water for a few 

 minutes before use. All dead animals, slime, or effete matter should be 

 removed by means of a pair of long boxwood forceps or small saucer, as 

 soon as noticed. With a moderate amount of attention, a marine aqua- 

 rium may be kept for years (ten or more) without changing the water. 

 Microscopes are specially constructed by Mr. Highley, Mr. King, and 

 Mr. Salmon, for observing animals within aquaria. See p. 13. 



The most useful books to the microscopist visiting the coast, will 

 be found in the list at the end of the volume. 



248. Examination of Lower Animals during Life. Many of 

 the lower animals may be examined in the living state, and numerous 

 interesting and important facts may be demonstrated. The student 

 will find many of the smaller insects, more especially the aquatic 

 larvae, as for example, those of the common gnat, well adapted for 

 this purpose. Small crustaceans, as the daphne and some of the 

 fresh water shrimps are exceedingly interesting objects, and are 

 easily subjected to examination in the living state in the animalcule 

 cage, p. 66, or under a compressor ium, p. 81. 



Examination of Infusoria, &c. Suppose the student desires to 

 submit some of the animalcules in water to microscopical examination, 

 he may proceed as follows. A drop of the water is to be removed 



