200 



NA TURE 



{Jan. i, 1885 



Saturday are reported from Antequera, and nine from 

 Archidona. That the disturbance has not yet ceased is 

 shown by the report from Torrox that the shocks were 

 renewed there on the morning of the 29th, shaking the 

 foundation of the Town Hall, and causing cracks in the 

 walls of other houses ; while other violent shocks are 

 reported from Malaga and Granada on the evening of the 

 30th, one at 7 and the other at 10 o'clock. In connection 

 with these after- shocks, a report from Tarvis, in Carinthia, 

 states that an earthquake was felt there on Sunday, which 

 by the oscillation it caused cracked the walls of many 

 houses. The Spanish earthquake was not felt in the 

 north and north-western provinces. No precise informa- 

 tion as to the times of the shocks at the various places 

 has been received. At Xerez and Cadiz, according to 

 one account, the first smart shocks occurred shortly 

 before 9 o'clock, and other slighter shocks about mid- 

 night and 4 o'clock the next morning. At Ciudad Real 

 no damage appears to have been done, beyond the alarm 

 to the inhabitants, who passed the night in the open, 

 fearing a recurrence of the shocks. At Velez Malaga and 

 Malaga proper several shocks injured the theatre and the 

 churches, the falling masonry killing several persons. 

 The clocks are stated to have stopped in various parts of 

 Andalusia at from ten to seven minutes before nine, which 

 may therefore be taken as the time of the first shock. 



We have received the following correspondence on the 

 subject of the earthquake : — 



Yesterday, 25th, at Sh. 53m. p.m., slight earthquake 

 in Madrid : two distinct shocks in 3 to 5 seconds ; house 

 bells set ringing and lamps and other suspended objects 

 swinging ; the oscillations were almost due east and west, 

 which gives north and south as the direction (rough) of 

 seismic disturbance. This was evidently stronger in some 

 parts of the town than others, as out here it produced no 

 effect outside, whereas according to this morning's paper 

 much alarm was produced in some streets by people 

 rushing out of their houses. But earthquakes are very 

 uncommon in Madrid, and this accounts sufficiently for 

 the scare. There really was no particular cause for 

 alarm. Official telegrams report shocks felt at about the 

 same time in Cadiz, Malaga, Granada, and Cordova. 



F. GlLLMAN 



Ouintana, 26, Madrid, December 26, 1SS4 



I HAVE reason to believe that this commotion extended 

 to England. On the night of December 25 I left my 

 family quietly seated round the fire at 10 o'clock. Being 

 in bed myself at about 10.20, I perceptibly felt a shock of 

 earthquake such as I have often experienced in the 

 vicinity of Naples, and I said to my wife, who came up 

 shortly afterwards, " I have felt a distant shock of earth- 

 quake, if there is nothing moving downstairs," which from 

 the distance of the offices there certainly was not. The 

 motion, we learn, was from south to north, and the usual 

 rate of movement corresponds well with the time of the 

 occurrence — say 6 minutes to 9 at Madrid. 



The Rookerv, Ramsbury, Wilts ALFRED BATSON 



THE HABITS OF THE LIMPET 



'THE following observations upon the habits of the 

 *- common limpet {Patella vulgata) were made during 

 last July at the Scottish Marine Station, Granton, Edin- 

 burgh. I am much indebted to Mr. John Murray, the 

 manager of the Station, for kindly placing its resources 

 at my disposal, and a'so to Mr. J. T. Cunningham, B.A., 

 the director, for much kind advice and assistance. 



The Ark is moored in the centre of a flooded quarry, 

 upon whose faces large numbers of limpets are to fie 

 found. As parts of these faces are almost or quite ver- 

 tical, it was easy to take a boat round and make observa- 

 tions during all states of the tide. The few that were 



made bear on the feeding and locality-sense of the form 

 in question. 



By far the larger number of limpets "roost" upon rocks 

 whose only covering consists of minute green algse and 

 nullipores, together with numerous acorn barnacles. 

 These last are seen to be of very unequal degrees of 

 " cleanness," some being covered with vegetable growth, 

 others quite white and bare. Those immediately sur- 

 rounding a limpet or group of limpets are invariably 

 free from algae. As might have been anticipated, Patella 

 is the cause of this freedom. At low tide anyone on the 

 look-out can hear a quick, regular, rasping sound in all 

 directions, and see numerous limpets slowly crawling 

 about. Scrutiny of any particular individual shows that 

 the rasping noise is caused by strokes of the radula, 

 which speedily scrapes away the incrusting alga;. Whilst 

 " on the feed " a limpet moves steadily on, pretty much 

 in a straight line, and continually sweeps its elongated 

 snout from side to side, feeling out probably suitable 

 patches whereon to graze. When such a one is dis- 

 covered, it is gradually licked quite clean. If the patch 

 happens to be the surface of a moderate-sized barnacle, 

 the circular lip is completely spread over it, almost tempt- 

 ing one to believe that the crustacean is about to be 

 '■ sawn out." Such, however, is not the case, " house- 

 cleaning " being the sole end in view. Indeed, limpets 

 are often serviceable to one another by thus clearing 

 away esculents growing upon their shells. To secure a 

 dinner, a good deal of licking is requisite, and perhaps 

 this habit may help to account for the inordinate length 

 of the tongue-ribbon. Certainly it must be used up at a 

 very great rate. 



But this is not the only, though I believe' the chief, wa) 

 in which the limpet feeds. Those individuals which live 

 near large sea-weeds, such as Fucus, feed extensively 

 upon them, as their gnawed condition testifies. I can 

 speak confidently in this matter, having caught more than 

 one limpet in the act. The operation was as follows : — 

 The edge of a thick flat part of the thallus was seized by 

 the lip (as a traveller might commence on a colossal 

 sandwich), and being, I suppose, held firmly by the upper 

 jaw, a semicircular "bite "was gradually excavated by 

 successive scrapes of the radula, the edges of the bite 

 being bevelled on the under side. So far as my observa- 

 tions extended, limpets do not feed when covered by 

 water, but always settle down firmly before the rising tide 

 reaches them. The intervals between which any p Macular 

 limpet feeds seem to be very irregular ; but, as a rule, 

 the largest limpets are apparently least fond of long fas ^. 



In regard to the second point, the locality-sense, great 

 doubt seems to exist in the minds of naturalists as to whether 

 limpets go back to the same place to roost. I believe the 

 question was answered in the affirmative long since by a 

 Mr. King, but. as far as is known tome, he did not publish 

 any details of his observations, and this is my excuse for 

 giving an outline of mine. Following a suggestion of 

 Mr. Murray, I marked a number of limpets with white 

 paint, and made corresponding marks near their " scars " 

 with a view to " keeping my eye on them." As Dr. S. 

 1'. Woodward remarks, it seems probable from an a prion 

 point of view, that limpets have a settled home, for the) 

 occupy scars, often sunk to a considerable depth, which 

 exactly correspond to the outline of the shell. My ob- 

 servations, made on numerous specimens of various sizes, 

 completely confirm Mr. King's opinion, and the method of 

 marking rendered cases of "mistaken identity" quite out of 

 the question. The greatest distance from its scar at which I 

 noticed a marked limpet to be, was about three feet ; yet 

 this distance, though extremely rough, and covered with 

 barnacles, was re-traversed without difficulty. The ex- 

 cursions from the roosting-places were made in an\ 

 direction where food offered ; so there were nothing like- 

 beaten tracks formed. But a limpet always returns 

 home before the rising tide reaches it, and invariably 



