HARD WICKE'S SCIENCE- GOSSIP. 



•187 



the Italian herdsmen and boys phick up the flower by 

 the roots, and offer it for sale to travellers ; and no 

 doubt they destroy every plant they can find. The 

 local authorities and the Austrian Alpine Club have 

 taken the matter in hand, in the hope of preserving 

 the plant on the mountains ; but it is hardly likely 

 they Avill succeed, so long as travellers can be met 

 with who are willing- to become purchasers. — 

 T.B. W. 



Shining Moss. — If you think the following would 

 be in any way interesting to the readers of Science- 

 Gossip, will you kindly insert it in your August 

 number. There is near Portsmouth, Lancashire, 

 a narrow tunnel, made by miners for the purpose 

 of working the coal. This tunnel is many years 

 old, and its sides are covered with a very minute 

 moss, which, when seen from the mouth of the 

 tunnel, has a very delicate green metallic lustre. On 

 going into the tunnel (about 5 feet high) this lustre 

 is not seen, and the moss itself is nearly invisible. 

 Its botanical name is Schistostega' peiinata. Could 

 any correspondent give other instances of shining 

 moss ? Is not the moss very rare ? — T. J Vat son, 

 54, Bank Parade, Burnley. 



Alth.^a hirsuta IX Gloucestershire. — The 

 readers of SciENCE-GossiP may be interested in the 

 occurrence of this rare plant. Yesterday, in a ramble 

 in search of some of the botanical treasures which 

 abound in our neighbourhood, I passed over Pur 

 Down towards Stapleton, and was delighted to find 

 this rare member of the Mallow tribe. From its 

 situation I see no reason to doubt its claim to a 

 place in our flora. The south side of the Dov/n was 

 covered with a splendid grove of old beeches, and I 

 have repeatedly observed the almost entire absence 

 of vegetation under their shade ; some time ago 

 most of these trees Avere felled, and it was round one 

 of the old stumps the marsh mallow sprung up. 

 The stems of all the plants are procumbent, and the 

 colour and general appearance of the flowei^s similar 

 to the common marsh-mallow {A. officinalis), but 

 smaller, while the calyx, bracts, and the whole plant, 

 are rough with erect hairs. Bentham describes the 

 flowers as pale purplish-blue : these are a pale pink, 

 with white stamens. In a shady lane leading from 

 the Down into the Stapleton road, many plants of 

 Cardami7ie impatiens were in fine flower. — W. E. 

 Green, Bristol. 



GEOLOGY. 



Volcanic Cones. — At the last meeting of the 

 Geological Society, Mr. Robert Mallet, F.R.S., read 

 a paper on "A hitherto Unnoticed Circumstance 

 affecting the Piling-up of Volcanic Cones." After 

 some remarks upon the two forms of volcanic activity, 

 the earlier system of "fissure eniption," and the 

 present one of " eraption at explosive foci," which 



he did not think could be carried back much beyond 

 the Tertiary epoch, the author discussed the ordinary 

 method of formation of a volcanic cone, and pointed 

 out that the effect of the piling up of material must 

 produce a pressure on the original surface commen- 

 surate with the amount of material heaped up on it, 

 and therefore increasing gradually from the circum- 

 ference nearly to the centre of the cone, where the 

 loftiest column of material presses upon the unit of 

 space. When the supporting rock is unyielding, 

 such as the granite which bears the Puys of Auvergne, 

 it will probably maintain its original position ; but 

 when it is of a more yielding nature, as in the case 

 of the ordinary stratified rocks, the pressure of the 

 cone will produce a saucer-shaped depression, 

 deepest in the centre where the greatest pressure 

 occurs ; and this tendency to sink will be aided 

 materially by the honeycombing and evisceration of 

 the subjacent rock-masses exposed to the action of 

 the volcano. The consequence of this depression 

 of the surface supporting the cone will be to diminish 

 the original slope of the successive superimposed 

 deposits, and even in some cases cause the lowest 

 beds to slope from the circumference towards the 

 centre. If the strata upon which the volcano stands 

 be particularly plastic, its pressure may cause an 

 uprise of the strata into protuberances round the 

 foot of the mountain. Similar phenomena may 

 occur when the support of the cone is formed by 

 older volcanic deposits. 



The Insect Fauna of the Secondary 

 Period. — A short time ago we stated that Mr. H. 

 Goss, F.L. S., had read a, very important paper on 

 the Insect Fauna of the Tertiaiy Period before the 

 Brighton and Sussex Natural Histoiy Society. The 

 latter society has recently had the opportunity of 

 hearing another paper by the same industrious natu- 

 ralist, on "The Insect Fauna of the Secondary 

 Period," which is even a better geological summary 

 of all that is known of insect fossils than the pre- 

 ceding. Our knowledge of this department of 

 paleontology has been veiy vague and untrustworthy, 

 and we are therefore pleased to see Mr. Goss de- 

 voting his time and abilities to the subject. The 

 latter paper is reported in full in the Sussex Daily 

 News of June 15th. 



New Species of Fossil Bird. — Mr. AY. H. 

 Shrubsole, of Sheerness, has been fortunate enough 

 to discover in the London clay of the Isle of Sheppy 

 some large fossil bones, which Professor Owen states 

 are those of a gigantic bird called Lithornis cmuinus. 



Note on a Probable Cause of Faults in 

 Limestone. — I have for some time strongly suspected 

 that some of the Faults and dislocations so frequent 

 in limestone rocks may not be due to plutonic 

 agency, but to a cause more constantly at work, and 

 which is chemical, rather than mechanical. It is 

 well known that the water falling in the form of rain 



