HARDWICKE'S SCIENCE-GOSSIP. 



i5 



oxygen, but consume the carbonic acid gas which is 

 perhaps the greatest enemy to the aquarium. 



Sea-weeds, however, must be obtained growing on 

 a stone or shell, for if once removed, they will never 

 attach themselves again. 



The best sorts are Bryopsis plnmosa, Cladophora 

 arcla, the common sea-grass {Enteromoipha com- 

 pressa), and the green laver {Ulva latissii/ia), and 

 may all be found fringing the beautiful pools at low 

 water. 



Regarding the inhabitants of the aquarium, great 

 care must be taken only to choose those which will 

 agree well together, or it will become the scene of 

 many battles, and the home of many slain. 



The great question then arises, What are the 

 animals most hardy and suitable, and how many are 

 we to introduce into a small aquarium ? I will suppose 

 that the various Algae have been placed together with 

 the sea-water in the vessel which is now ready to 

 receive the animals we have collected. 



The common periwinkle will be found a very 

 pleasing inhabitant, and being exclusively a vegetable 

 eater tends in a great measure to keep the sides 

 clear from that green scurf which constantly accu- 

 mulates and soon conceals the contents of the 

 vessel from distinct observation. I should not 

 recommend, however, the use of more than five 

 or six. 



One or two limpets {Patella vulgata) will also be 

 of interest, and are useful when a quantity of the 

 common laver {Ulva latissii/ia) is growing on the 

 shell. Perhaps the most beautiful objects in the 

 aquarium are sea-anemones, and these may be easily 

 found, greatly differing in size and colour, on the 

 rocks at low water. Great care, however, is necessary 

 to detach them, for if the base be injured, death 

 often ensues. 



The most common is the smooth anemone {Actinia 

 mesembryanthemum). There are many others ; but 

 two or three will be enough, and they should be 

 chosen of moderate size. Anemones may be fed 

 every two or three weeks with small pieces of raw 

 beef. 



Two or three fish, either the smooth blenny {Blen- 

 nius pholis), or the one-spotted goby {Gobius unipnnc- 

 tatus), give a lively appearance to the water. A 

 few prawns are interesting, and are also useful 

 scavengers. 



If a constant supply of salt water cannot be obtained, 

 a little fresh water must be added from time to time, 

 to make up that which is lost by evaporation. These 

 few hints are only intended for those who keep, or 

 mean to keep, small establishments. Those who 

 intend going in for large aquaria should study " The 

 Aquarium," by J. E. Taylor, F.L.S. 



A few rules in conclusion : Keep the vessel in a 

 light, airy situation : do not overstock it : be careful 

 to remove any dead animals at once : and try to 

 imitate nature as closely as possible. 



THE "ROSE OF JERICHO "-ANASTATIC! 

 HIEROCHUNTICA. 

 A MONG the seventeen hundred species comprised 

 ■iV in the important natural order Crucifene, one 



of the most remarkable is the " Rose of Jericho," of 

 which the lengthy and by no means euphonious 

 botanical name is given above. This plant does not 

 present any marked deviation from the prevailing 

 morphological characters of the order, and, therefore, 

 is in this respect less interesting than the tetra- 

 cotyledonous Schizopetalon, Pringlea antiscorbutica 

 (the Kerguelen Island cabbage), and others ; but it 

 is the peculiar hygrometric properties of the stem and 

 branches that have rendered it famous. The species 

 under consideration is the only one of the genus, and 

 forms, according to some authorities, the type of a 

 distinct tribe, Anastaticese ; it is a native of the dry 

 sandy tracts of land that extend from Syria to Algeria,, 

 being especially abundant in the neighbourhood of 

 Suez and Jericho. To the latter place it owes its 

 specific title, for hierochuntica (or hierochuntina) is 

 an adjectival form of the old name of that city ; how 

 the popular term Rose came to be applied to it is not 

 very clear, for there is not the remotest resemblance 

 to the queen of flowers, unless the dried-up ball may 

 be considered suggestive of its outline. 



The plant has recently been correctly and graphically 

 described by the veteran botanist, Mr. J. Smith, ex- 

 curator of the Royal Gardens, Kew, in his excellent 

 little work entitled " A History of Bible Plants." * 

 After detailing certain passages of the Scriptures 

 which are supposed to refer to the Rose of Jericho, 

 he proceeds as follows : — "It is an annual, having a 

 tap-root from which numerous branches are produced, 

 forming a circular disc about a foot in diameter, at 

 first lying nearly flat on the ground. It has small 

 leaves, and small white flowers at their axis. When 

 the seeds are perfected, the stems become dry, 

 hardened, and incurved, their points meeting and 

 forming a skeleton hollow ball, which in time (by the 

 power of the wind) loses hold of the ground, and, 

 being blown about, rolls and turns like a wheel." 



This description conveys a very good idea of the 

 plant, and we need only add that the fruit is a 

 small roundish silicula with two woody valves, each 

 of which terminates at its apex in an acute point. In a 

 botanical work of considerable note, these siliculte 

 have been strangely confounded with the flowers. 

 During the dry season these plant-balls are scattered far 

 and wide by the winds, and on the return of the rains 

 the branches spread out, the diminutive silicube burst 

 and release the seeds which speedily germinate in 

 the damp, warm soil. This alternative inclosing and 

 expanding of the branches continues for many years, 

 thus forming a most admirable and astonishing means 

 of effectively dispersing the seeds. Concerning the 

 strange manner in which these plants are scattered, 



* Published by Mr. David Bogue. 



