246 



KNOWLEDGE. 



[NOVEMBEK 1, 1895. 



large quantities nowhere outside the province of Pisa. 

 Of so-called alabasters there are legion. They occur in 

 the Tyrol, in Saxony, in Derbyshire, and many other 

 places ; but most of them, like the Oriental alabaster, are 

 a form of carbonate of lime. Even where the alabaster is 

 alabaster, it is frequently so poor in quality and so lacking 

 in beauty and fineness of texture, that it is subjected to 

 the base process of being ground to a powder to make the 

 well-known plaster of Paris. But the Pisan alabasters 

 are simply incomparable. All possess a marvellous softness 

 of texture, and some can even be scratched with the finger- 

 nail. But the rarest and most expensive of all alabasters 

 is a yellow one found at Volterra. This city has been 

 famous for its alabaster from time immemorial. 



Four thousand years ago its alabaster quarries, if they can 

 be so described, were in full swing, and they have probably 

 been worked continuously ever since. The Palazzo 

 Pubblico of this ancient Etruscan city contains a rnuseum 

 rich in priceless antiquities, among which cinerary urns of 

 alabaster play a prominent part. In the days of the 

 Etruscan league when Volterra was a city of much 

 importance, with a population numbering one hundred and 

 twenty thousand, its walls, forty feet high and thirteen feet 

 thick, enclosed a space four and a half miles in circum- 

 ference. Beyond the crumbling ruins of this mighty 

 barrier lie the alabaster caverns. Quarries they cannot be 

 called, for the mineral is not extricated in the open, but 

 dug out of caves, the entrance to which is often by way of 

 a long and winding passage. No shafts are sunk from the 

 outer air, so that the ventilation is none of the best, and the 

 atmosphere is hot and stifling, as may be readily under- 

 stood when it is stated that some of the caves are reached 

 by subterranean passages a mile in length. This necessi- 

 tates the quarry men working in short shifts of two hours, 

 and no underground workman is allowed to labour more 

 than six hours per day. In spite of this, however, alabaster 

 getting is held to be healthy work, the white impalpable 

 dust which each worker must inhale in large quantities, 

 being considered antidotal to the diseases common to the 

 district. Be that as it may, the alabaster workers are 

 certainly as healthy and long-lived as their comrades who 

 labour in the open. 



The alabaster is found in nodules or detached blocks 

 imbedded in clay or limestone, and great care has to be 

 taken in extricating these so as not to reduce the size of 

 the piece. 



The freshly-wrought alabaster is either exported or 

 disposed of to the carvers or sculptors, or to the proprietors 

 of fine art galleries who engage sculptors to carve statuary, 

 flowers, etc. Many carvers, however, prefer to work for 

 their own hand and buy their alabaster direct from the 

 owners of the mines, trusting to sell their finished work to 

 customers direct, or failing this to the middlemen who 

 own the galleries. Much of the raw material, however, 

 is not worked up at Volterra but is sent ofl" to Florence, 

 Leghorn, or Pisa, where there is a better chance of 

 obtaining patrons. 



At first sight it seems difficult to account tor the 

 declining character of the alabaster industry. But one 

 cause which has operated in this direction is the poor 

 taste displayed by the carvers and sculptors of alabaster 

 articles. The artistic instincts of both English and 

 Americans have of late years undergone a very material 

 refining process, and what years ago might have been 

 dubbed elegant and pretty, would, according to our better 

 hghts, be considered as a grave oft'ence against the canons 

 of correct taste. Everyone is familiar with the wonder- 

 fully-carved alabaster flowers, or fruit, or florid vases 

 which our sea-going friends insist we shall religiously 



preserve under a glass case as a treasured possession. 

 These are bad enough in all conscience ; but what can 

 be said of alabaster models of steamships carefully and 

 elaborately carved in full detail, even to the propeller, the 

 whole supported upon pediments of alabaster as a ship 

 rests upon the blocks when in graving dock ? For our 

 American friends there are statues of Liberty, Brooklyn 

 suspension bridges. New York hotels with real windows 

 of coloured glass, through which the light of diminutive 

 candles may shine. All these, it must be admitted, are 

 most faithfully executed, but of artistic feeling there is 

 Uttlfi or none. Italian carvers, too, seem to think that 

 nothing is so pretty and effective as an alabaster picture- 

 frame ! 



The English climate, too, is all against alabaster. To 

 a certain extent the substance is soluble in water, and the 

 humidity of our atmosphere soon creates a roughness of 

 surface, which has a powerful aflinity for dust and grime. 

 A leaning Tower of Pisa in alabaster may be wonderfully 

 pretty, but to preserve the beautiful translucency it is 

 necessary to encase it, and the English nation has now 

 been educated above the once omnipresent glass shade. 

 Clearly, the alabaster industry is at present under a cloud, 

 which shows little evidence of lifting. It may, however, 

 alter for the better when the artistic taste of the Italian 

 carvers improves, and they set themselves to reproduce in 

 miniature the truly beautiful works of art with which their 

 land abounds. 



ADHESIVE ORGANS IN ANIMALS. 



By K. Lydekker, B.A.Cantab., F.R.S. 



EITHER for the purpose of holding on to inanimate 

 substances, and thus securing protection from 

 attack or safety from the bufletings of the waves, 

 or by attaching themselves to the bodies of other 

 creatures, and thus obtaining an ample supply of 

 food without any exertions of their own, a considerable 

 number of animals have developed suckers, or other 

 adhesive organs, on some parts of their bodies or limbs, 

 and as these sucking-organs vary considerably in their 

 specialization and plan of structure in difterent groups, 

 their comparison forms an interesting subject of study. 

 In addition to these sucking-discs, which are purely for 

 the purpose of adhesion, there are in certain animals, such 

 as the lampreys and leeches, suckers formed by the mouth, 

 thus enabling the fortunate owners of such organs not only 

 to attach themselves, but likewise to procure their food by 

 devouring the blood or flesh of the animal to which they 

 are temporarily fastened. 



Probably the simplest, although nevertheless a highly 

 efficient, type of sucker are those of the limpet, and of 

 certain other molluscs found on some parts of our coasts and 

 known as chitons. In these creatures the sucker is simply 

 the soft under surface of the body — the so-called foot — 

 which on being applied to any fairly smooth surface, and 

 the centre elevated by muscular action, at once forms a 

 sucking organ without any special structural modification. 

 And it is probable that in a considerable number oi 

 instances suckers have originated from a portion of the 

 general surface of the body having been used in this 

 manner, and finally developing structural modification. 

 Suckers, as everybody knows, are very commonly present 

 in insects, but are much more rare among the higher 

 animals and molluscs, and it is therefore chiefly from the 

 two latter groups that our examples of these peculiar 

 structures will be drawn. 



Among mammals, suctorial discs are a very unusual 



