lee. 28, 1876] 



NATURE 



ij7 



lemory, for I often in imagination fight again my battles with 

 alibut and skate, lobster and cod, and the words " sea fisheries" 

 ave not altogether lost their charm ; but I confess I wholly 

 verlooked Prof. Newton's interesting letter on the subject, and 

 irned back the file of Nature and read the letter in connec- 

 on with Mr. Holdsworth's. The theory of the former appears 

 ) me to be the correct one ; the Atlantic sea fishery is being 

 radually played out. 



I doubt whether we can 'anywhere along its extensive coast 

 ow meet with "shoals" of mackerel or "schools" of herring 

 jveral miles in breadth, forming a mass of so compact a nature 

 lat small vessels had almost as much difficulty in getting through 

 lem as Sir George Nares had in getting through the so-called 

 alseocrystic ice, or hear of single hauls of 1,000 barrels ! And 

 at such was possible not twenty- five years ago. 

 The great mischief is done, certainly in America, by trawling, 

 his must he evident if one will but consider the modus operandi, 

 y which the female fish are captured just before they have de- 

 3sited their spawn, a few thousand fish so taken representing 

 le nonexistence of many millions. The subject has received 

 le most serious attention of the Canadian Government, and has 

 it been brought under the notice of the United States and 

 rench authorities. 



Mr. Holdswortli appears very much amused to find that Prof, 

 ewton has discovered a use for dogfish over and above his own 

 stance, in which it served as " salmon " for the Preston weavers, 

 at as we have never heard that the fishermen of Morecambe 

 xy were charged with feloniously administering a poison to the 

 id weavers, we must conclude that dogfish is a wholesome, but 

 rhaps not a toothsome, article of food. 



Mr. Holdsworth says that with this exception he has never 

 ard of a case in which " the hated dogfish was not knocked on 

 e head and thrown overboard whenever there was a chance of 

 doing." I can tell him one. Along the American coast the 

 gfish is certainly knocked on the head, but the fishermen there 

 ow its value too well to throw it overboard ; they keep it, and 

 yields an oil ; and of the many millions of gallons of "fish-oil" 

 the returns, " dog-oil " forms no inconsiderable portion. 

 There can be no doubt that the American fishermen, if they 

 d had their say in creation^ would have vetoed dogfish ; but 

 they had not, they came to the conclusion 'that there was 

 ubtless some wise purpose even in that' creature : a thorn in 

 i flesh to try their tempers and their nets, but one which they 

 ced to bear fruit. 



If it is true that the nets of the Donegal fishermen in 1875 

 re constantly full of dogfish, and they driven to their wits' end. 

 lope some Donegal reader of Nature will kindly read them 

 s letter ; it may be the means of opening up a glorious future 

 Ireland. Perhaps too some Lancashire reader will give the 

 )recambe Bay fishermen a hint, in case the Blackburn weaver 

 )uld hereafter have a surfeit of " salmon," and those practical 

 ers' occupation be gone. 



Vlay I in conclusion be allowed to dissent from Prof. Baird's 

 ral of " alewife?" He calls it "alewives." There is nothing 

 the meaning of wife in the word. This species of herring, 

 ich usually goes by the name of gaspereau, is also called ale- 

 'e, which is a corruption of the Indian word for a fish, adoo/. 

 e plural, I think, should be " alewifes." B. G. Jenkins 

 )ulwich, December 18 



Sense of Hearing in Birds and Insects 



do not know whether ornithologists are acquainted with the 

 uliar manner in which curlews frequently obtain their food 

 landy flats which have been left bare by the tide. The birds 

 ;e their long bills into the wet sand as far as the nostrils, and 

 1 again withdraw it, leaving a small hole , which, when probed, 

 ound to be only just large enough to have taken in the bill. 



animal, therefore, can only have made a single prolonged 

 h without adding any lateral or exploring movements of the 



as birds which feed in mud may be observed to do. Now it 

 lot be supposed that curlews adopt this mode of feeding 

 lOut obtaining from it some degree of profit. Neither can it 

 upposed that they make their thrusts into the sand at ran- 

 i ; for, their bills being so pointed and slender, the birds would 

 Hilly require to make a vast number of inefleclual thrusts before 



happened to hit upon a worm or other edible object. The 

 tion therefore is, How do the birds know the precise spots 

 re their victims lie buried in the sand ? That this knowledge 



t derived by sight I am quite sure, for I have repeatedly 

 rved innumerable curlew marks of the kind described occur- 



ring on tracts of sand which, in virtue of their high level, pre- 

 sented a perfectly smooth and uniform surface. I can therefore 

 only suppose that the birds are guided in their probings by their 

 sense of hearing. Doubtless it is difficult to believe that this 

 sense is so delicate and precise as to enable the curlew to per- 

 ceive so exceedingly slight a sound as that which must be caused 

 by the movement, say, of a small worm at a distance of ten or 

 twelve inches from the surface of the sand, and at the same time 

 to localise the exact spot beneath the surface from which so 

 slight a sound proceeds. I cannot see, however, that any other 

 explanation is open, and perhaps the one now offered may not 

 seem so incredible if we remember the case of the thrush. No one, 

 I think, can observe this bird feeding and doubt that it finds its 

 worms and grubs almost exclusively by the sense of hearing. And if 

 the distance which it runs between successive pauses for listening 

 represents — as we cannot but suppose it must — the diameter of 

 the circle within which this bird is able to hear the movements 

 of a worm, I think that the hypothesis I have just advanced with 

 regard to the curlew ceases to be improbable. 



It seems worth while to add a few words with respect to the 

 sense of hearing in insects. So far as I am aware, the occurrence 

 of such a sense in this class has never been actually proved, 

 although on d priori grounds there can scarcely be any doubt 

 concerning the fact of some insects being able to hear ; seeing 

 that in so many species stridulation and other sounds are made 

 during the season of courtship. In the case of moths, however, 

 I believe that sounds are never emitted — except, of course, the 

 death's-head. It therefore becomes interesting to observe that 

 an auditory sense is certainly present in these insects. Several 

 kinds of moth have the habit of gently, though very rapidly, 

 vibrating their wings, while they themselves are at rest on a 

 flower or other surface. If, while this vibrating movement of 

 the wings is going on, the observer makes a sudden shrill note 

 with a violin or fife, &c., the vibrating movement immediately 

 ceases, and sometimes the whole body of the insect gives a 

 sudden start. These marked indications of hearing I found 

 invariably to follow a note with a high pitch, but not a n.ote with 

 a low one. George J. Romanes 



" Towering " of Birds 



I HAVE read Mr. Romanes' communication on the "tower- 

 ing " of grouse and partridges with much interest. As he re- 

 quests further information, may I be permitted to contribute the 

 following : — I once observed a pheasant which, after being shot, 

 flew apparently untouched for about one hundred yards, then 

 towered ten or fifteen yards, and fell dead. As a rule birds that 

 have towered are picked up dead, as Mr. Romanes states ; but 

 such is not invariably the case. A correspondence took place in 

 ih.e Field some weeks since in answer to the question: "Do 

 towftred birds ever rise again," and several replies were elicited 

 in the affirmative. The conclusion warranted by that correspond- 

 ence seemed to be that towering arises from at least two distinct 

 kinds of injury. In the first, the common form, the bird is 

 struck in the back, and is always found precisely where marked 

 down. It seems to me that in this kind of towering \.\\q perpen- 

 dicular flight may be attributed to a cause perhaps other than, 

 or at all events additional to, puhnonary haemorrhage. I con- 

 sider that haemorrhage is a necessary factor, and Mr. Romanes 

 makes out a very strong case in favour of its being into the 

 lungs. That the movements of the wings are convulsive, and the 

 explanation of the towering, I am not inclined to dispute, but I 

 think it has yet to be proved that the convulsive flapping of 

 wings (the directing power of the brain being in abeyance) 

 always produces perpendicular and never merely erratic flight. 

 Every towering bird acts in a precisely similar way. Are we to 

 take it for granted that in asphyxia it is only certain sets of 

 muscles, and these always in the same and to an equal degree, 

 that are spasmodically affected ? I have noticed that a towering 

 bird very often has his legs hanging straight down (I do not 

 allude to those cases where they aie palpablj* mutilated), and it 

 strikes me as being likely that paralysis of the legs and lower 

 part of the back may have something to do with the flight being 

 upward. A man who has paraplegia always complains that he 

 cannot move his legs because they are so heavy. This sensation 

 would doubtless be felt by a bird paralysed behind, and this, in 

 addition to the loss of its steering apparatus and the co-operating 

 contractions of the posterior muscles, would produce a loss of 

 balance with much the same effect as though the after parts had 

 really become disproportionately heavy. I have no desire to be 



