HARDWICKE'S SCIENCE-GOSSIP. 



177 



The plan we have adopted, is to watch, when the 

 tide is low, from about n A.M. until 2 p.m., by 

 the pier, or on the sands. When you observe the 

 elegant creatures floating in or near the surface of 

 the water, then gently dip] the coffee cup beneath 

 them. 



They are thus easily caught, without in the least 

 degree injuring the long and beautiful cilia. When 

 you bring them home, make an aquarium from a 

 good-sized brown glazed earthenware pan-mug, with 

 a tolerably wide base, somewhat like those used by 

 milk-dealers ; it should contain not less than five 

 gallons of sea-water. Before placing your Medusa in 

 this improvised tank, purchase a plain colander, as 

 used by the cook, from any ironmonger, and allow it 

 always to rest in the aquarium, thus, by lifting it 



are flexible capillary tubes, having lateral short 

 branches ; these tentacles descend from the under part 

 of the creature, and diverge from each other. We 

 are told that their surface is covered with minute 

 vesicles, by which they probably seize and hold their 

 prey. In the evening, if disturbed suddenly, they 

 throw out a faint phosphorescent light, appearing 

 like a luminous twisted column continually changing 

 with the varying gyrations of the Cydippe. The 

 body is a little melon-shaped sphere, like pure 

 crystal ; thus, when they eat, the food may be watched 

 traversing the whole of the transparent tissue. Then- 

 sides are fringed with mobile cilia, partly by which 

 they move through the water like little balloons. 

 They also rise in the water like bubbles, and as 

 suddenly descend again ; sometimes this is carried on 



Fig. 97. — Cydippe, or Pleurobrachia j>ileus (from Taylor's " Half-hours at the Seaside"). 



gently, the Medusa can be taken out at any time 

 w ithout any permanent injury, and placed singly in 

 a large confectioner's jar for immediate study. By 

 means of the earthenware jar, they are kept at an 

 equable temperature, and just sufficient light is 

 admitted to be healthy for them, and without incon- 

 venience or trouble they can be preserved all the 

 summer months to be the delight of any visitor, or 

 the joy of all the household. 



Now, for a moment, allow us to give a quiet and 

 homely lesson upon these v. onderful jelly-fishes, or, 

 as they are often named, sea-nett'es. They are all 

 glassy-looking, from the transparent gelatinous bodies 

 which in the case of the one we are now noticing, the 

 Cydippe, or Pleurobrachia pilcus, very commonly seen 

 floating on the surface of clear water in the sea, or 

 tidal rivers they are furnished with two very fine and 

 delicate tentacles, six times longer than its body ; they 



slowly, but it is elegant indeed when they turn round, 

 as it were on an axis, which was compared by one of 

 my children to a dancing dervish ; in these rapid 

 motions, the tentacles float after it. 



Nicholson thus describes the digestive apparatus : 

 " The mouth of Pleurobrachia opens into a spindle- 

 shaped digestive sac, or stomach, which in turn opens 

 below into a wider and a shorter cavity termed the 

 funnel ; from this there proceed in the axis of the 

 body two small canals, which open at the opposite 

 pole of the body. The funnel communicates with a 

 complicated system of canals, which are ciliated 

 internally, and are filled with a nutrient fluid. In 

 the angle between the two canals which run from the 

 base of the funnel to the surface is a little vesicle, 

 or sac, believed to be a rudimentary organ of 

 hearing, and placed upon this is a little mass which is 

 generally believed to be of a nervous nature. The 



