128 



HARDWICKE'S SCIENCE-GOSSIP. 



MY EXPERIENCE OF MARINE AQUARIA. 



PERHAPS a statement of my recent experience 

 in starting a Marine Aquarium may be of service 

 to " Rita" and otliers. 



Wishing to observe the development of some 

 marine microzoa, I obtained a confectioner's glass 

 cake-cover, eight inches in diameter, inverted it upon 

 a block of wood in which was a hole to receive the 

 knob, and on the bottom, put a layer of fine gravel 

 previously washed quite clean. Then I collected a 

 few pebbles to which healthy fronds of Ulva and 

 some of the smaller algae were attached. 



These were well rinsed in sea-water, and placed in 

 position among the gravel. The only other necessary 

 operation was to get some more sea-water, let it 

 stand till quite clear, and then to fill up the glass to 

 about an inch from the top. This was soon done, 

 and the aquarium was complete and in working 

 order for minute forms of life. 



I stood it on a window ledge, where it is exposed 

 to direct sunlight (when there is any) for several 

 hours daily. 



It will probably be necessary to lessen this expo- 

 sure as the summer advances. 



On the alg?e were colonies of various species of 

 polyzoa and other parasitic life which have thriven 

 well. At once, I noticed tiny crustaceans darting 

 about, and soon many other forms made an appear- 

 ance. 



Every few days I discovered something fresh and 

 highly interesting. 



During the severe weather, the aquarium was 

 frozen several times, but the only ill-effect noticed 

 was the destruction of a host of discoidal germs that 

 were dotted all over the interior surface of the glass. 

 Occasionally I have added other objects collected 

 during my rambles along-shore, and they have also 

 grown and multiplied. As a microscopist I can say 

 that this aquarium, with others of varying size, from 

 ten inches in diameter down to finger-glasses that I 

 have started since, have afforded me an immense 

 amount of enjoyment, whilst the expense has been 

 merely that of the cost of the glasses. 



Even without the microscope, I have found much 

 to observe and admire. 



^Vith a pocket-lens the habits of many of the 

 animals can be studied. 



Spiders that appear to be all legs and no body can 

 be seen twining themselves among the stems of 

 Tubularia so as hardly to be distinguished therefrom. 

 The comical Caprclla may be noticed gripping a stem 

 with the three pairs of strong claspers at its hindmost 

 extremity, and waving its grotesquely attenuated 

 body about in singular fashion. Or it may be that 

 one sees a small crab {IJyas aranais) perched in a 

 branching plant, as in a bush, hardly perceptible at 

 first sight because of the miniature forest of algas 

 and filamentous diatoms gromng upon its back. 



Though apparently motionless, the curious little 

 fellow is causing a current of water to flow past his 

 mouth, so that he gets a plentiful supply of food 

 without the trouble of running after it. 



Then there are beautiful worms crawling about, or 

 else swimming in graceful sinuosities. Or the out- 

 flowing current from some of the miniature craters 

 of a sponge colony may be detected throwing out 

 grains of sand or perhaps its own gemmules. 



To assist some winkles in keeping the glass clear 

 of vegetation, I put in a small slug, Eolis alba. One 

 day, I was astonished when I found that this animal 

 had deposited a host of eggs enclosed in a gelatinous 

 tube, and arranged in a symmetrical flat spiral coil 

 upon the glass. At intervals, other clusters of ova 

 appeared, and I have had the gratification of watch- 

 ing the progress of the embryos through numerous 

 changes, to me at once novel and wonderful. 



Each transparent capsule, at one stage, contains 

 several individuals, and it is very curious to see them 

 twirling and rolling about within, apparently causing 

 mutual discomfort. Some that were more exposed 

 to solar influence than the others, became so active 

 a few days ago, that they burst their prisons, and 

 started in life independently. Now they have a 

 glassy shell, somewhat nautiloid in form, into which 

 they can withdraw their ciliated lobes when tired of 

 roaming. 



Other changes must of necessity ensue before they 

 attain to nudibranchiate maturity, and these I hope 

 to observe with increasing interest. 



W. H. Shrubsole, F.G.S. 



Skec'7-i!i'ss-on-Sea. 



A CHAPTER ON ROSES. 



SO long have roses experienced the loving care 

 of man that it is not known when they became 

 garden plants, and so far back as the hanging gardens 

 of Babylon they were there carefully cultivated for 

 the pleasure of Queen Amytes. They dislike exces- 

 sive cold and heat, preferring to make their homes 

 in temperate climates. Pure air and shelter from the 

 winds they must have ; smoke is death to them ; 

 whilst nearly every species (and they are almost 

 innumerable) requires a particular soil and particular 

 treatment. They are to be found in Europe, and 

 parts of Asia and Africa, but have not extended their 

 travels to Australia, which does not possess a single 

 wild rose. In Gerarde's time, London must have 

 been beautiful with roses, for he speaks of nearly 

 all the kinds he describes as "growing in our 

 London gardens." It was probably in his own 

 garden at Holborn that he tried the experiment of 

 "grafting a wild rose on a broome stalk," and 

 therefore declines to credit the report that the 

 yellow rose was so originated. Lete, a merchant of 

 the metropolis, introduced the yellow rose from 



