170 



SCIENTIFIC NEWS. 



[Aug. 24, 1888. 



are those of an ancient lake formerly dammed by glaciers, 

 first to a height of 1,140 feet above sea-level, then 

 reduced by a breaking down of the dam to 1,059, tnen 

 to 847 feet. The Norwegian terraces are ancient sea- 

 shores, are in every valley there, and incomparably 

 more distinct. One may walk above forty miles along 

 some of them, as on an artificial esplanade, or sea-wall, 

 which only terminates when the height of the bottom of 

 the valley reaches its level. 



On my visit to Norway in 1856 I walked from Chris- 

 tiania to Trondhjem, and first observed them in the Gula 

 Valley, by which the road descends towards the sea. I 

 struck into this valley on descending from the Dovrefjeld, 

 near to where the upper terrace spreads out. to form the 

 bottom of the valley — i.e., where the bottom of the valley 

 is 600 feet above sea-level. Here was a fertile plain, 

 such as may be found at a corresponding elevation in most 

 of these valleys. Viewed thus from above, the terraces 

 were very puzzling, but their true nature was fully 

 revealed lower down. 



The tourist of the present day will run over this ground 

 by rail as I have subsequently, and in doing so will behold 

 a magnificent panorama of these terraces, extending for 

 miles not only along the main valley, but up the many 

 branches of the tributaries to the Gula, each terrace wind- 

 ing about at its respective level in an unbroken curve. 

 Referring to my diary, I find that I counted five in the 

 main valley, at fifteen to twenty miles' distance from its 

 mouth. These of course correspond to so many varia- 

 tions of relative land and sea level. Assuming that the 

 differences were due to upheaval of the land, there must 

 have been a series of great upheavals, with comparative 

 rest between, during which periods of rest the material of 

 these shores was deposited. The mode of deposition I 

 must not discuss. It opens a wide field of interesting 

 study, both of river deposition and glacier deposition. I 

 will only add that at the present moment similar plains 

 are to be seen on the sea-shore (as at Bodo, for example), 

 which if upheaved would be cut down by the river, and 

 thus form another and a lower terrace. 



The present period represents one of quiescence 

 between the upheavals, a period when there may be 

 earthquakes amounting to such tremblings as are now 

 occurring, but not sufficiently violent to cause a 

 measurable variation of sea-level and convert a sea-shore 

 plain into an estuary or valley terrace. 



THE NATURALIST AT THE SEA-SIDE. 



VI. Petrified Seaweeds. 



A T low-water mark on a rocky English coast begins a 

 -^ i- zone of bladder L wrack and tangle, which stretches 

 down into considerable depths. Where these seaweeds 

 fail, because 'the darkness grows too great for those 

 peculiar chemical operations on which their nutrition 

 depends, we find patches, sometimes miles in extent, 

 covered with branching and often jointed organisms of 

 stony texture and white, greenish, or purple in colour. 

 The old naturalists considered these to be allied to the 

 true corals, which indeed they resemble superficially, 

 and named them corallines, or sometimes nullipores, from 

 the absence of such pores as in most true corals lodge the 

 polyps. They are now ascertained to possess no animal 

 characters at all. Neither in nor around the stony 

 skeleton is anything of polyp-kind to be discovered. The 

 so-called skeleton is itself the living tissue — a mass of 



minute cells impregnated with carbonate of lime ; and 

 these cells are vegetable, and not animal. 



The corallines {e.g., Corallina officinalis) are small 

 branched and jointed plants, consisting of many flattened 

 fronds attached together by narrower articulations. If 

 placed in weak hydrochloric acid (1:10) they become 

 soft and flexible. Thin sections may then be cut and 

 examined in glycerine. The fronds will be found to 

 consist of crowded cells of rounded shape, which at the 

 articulations pass into much elongated cells, or fibres. 

 The cells are filled with granular protoplasm, and send 

 very delicate fibres of communication from one to 

 another ; the cell walls consist of cellulose, and after the 

 lime-salts are removed are very thin and fragile. The 

 whole frond is covered by a sort of epidermis ot 

 flattened and rounded cells, which secretes a tender 

 investing membrane. Reproductive organs, lodged in 

 little hollow capsules, are borne at the ends of the 

 branches. These are essentially similar to those of other 

 algae of the order Florideae. 



Nullipores (e.g., Melobesia) have unjointed branching 

 stems. They often encrust stones or other algae, but 

 some of the species have a tree-like mode of growth. 

 Even at low-water mark or in deep shore-pools, which 

 are never uncovered by the tide, claret-coloured crusts of 

 nullipores may be found. 



The colouring-matter of these curious plants is believed 

 to be the same red pigment which tinges so many flex- 

 ible sea-weeds. It is soluble in cold water, and may be 

 removed readily from crushed and powdered nullipores. 

 A green colour, previously masked by the red pigment, 

 then shows itself, and this turns out to be chlorophyll, the 

 ordinary colouring-matter of green plants. 



The calcareous matter enormously preponderates over 

 the rest of the tissues. It is no doubt obtained from 

 sea-water in a state of solution, and precipitated in the 

 cells. To this ingredient the corallines owe their rigidity 

 and a certain degree of immunity from the attacks ot 

 browsing animals. The sea-snails, which devour ordinary 

 seaweeds in vast quantities, cannot touch the corallines. 

 Some fishes, however, have strengthened the armature 

 of their jaws to such a point as to be able to grind up 

 even this hard provender. But it is indirectly, not as 

 food, but as a means of shelter, that the stony seaweeds 

 are chiefly serviceable to the crowd of animals which 

 throng the coralline zone. A bivalve (Lima) gathers 

 their broken branches, and weaves them with threads of 

 its own into a nest. Here many fishes lay their spawn 

 in safety, colonies of hydroid zoophytes spread their 

 feathery branches, and spider-crabs creep about what is 

 to them a petrified forest. When the naturalist's dredge 

 crashes through the spires and pinnacles of these sub- 

 marine cities many a shy recluse, never washed ashore 

 by winter gales, is dragged forth to the unaccustomed light 

 of day. 



The brittleness of the corallines determines their verti- 

 cal range. In shallow waters which are swept by 

 storms no slender and rigid architecture is possible. The 

 tough and flexible seaweeds are here in place. Where 

 corallines are found they give proof that the sea-bottom 

 is vexed by no waves, and that no currents bring sand 

 and mud to choke the rooted plants. 



Diamonds in Meteorite. — According to the American 

 Naturalist, at a meeting of the Philadelphia Academy of 

 Natural Sciences, a fragment of a meteorite containing 

 diamonds was exhibited by Professor H. C. Lewis. 



