September 1, 1898.] 



KNOWLEDGE. 



197 



known "cuckoo" is given with apparently no suggestion of 

 a further development than the doubling of the first note. 



The sedge warbler is much more inventive, for he 

 frequently creates an original strain by associating two or 

 three cries of other species, and repeating them m a certain 

 order and with a definite accent many times successively 

 in one song, thus proving what a single bird can do by 

 means of repetition, and indicating what mat/ he occurring 

 much less quickly in other species. 



In the thrush a few notes, often borrowed, are very 

 generally re[ieated a few times, but never prolonged, 

 as in the song of the sedge- warbler. The thrush, 

 indeed, seems to repeat from lack of originality, and yet 

 without sufficient persistence to produce striking strains. 



The nightingale is, however, the master of repetition in 

 song. The majority of his strains simply consist of one 

 or two notes repeated with varying speed, the whole song 

 including from two or three to twenty-five or thirty 

 repetitions of one note. I have counted as many as thirty- 

 three repetitions, given at about the rate of five per second, 

 and this number is probably often exceeded, though not 

 after the middle of May, when the song begins to wane. 

 The charm of the bird may be partly due to its repetitions, 

 for the ear is not so tired by them as by the rapid jerky 

 songs of the blackcap, and some other quick singers, but 

 may dwell on and enjoy each simple pure tone. The 

 nightingale has acquired a magnificent ci-esccndo : and one 

 cannot but surmise that human ideas of this grace in 

 singing may have been borrowed from the bird. The 

 sedge-warbler and blackcap, and perhaps the wood-wren 

 also, have imperfectly acquired it. 



The origin of some of the nightingale's strains may pre- 

 sumably be found in single cries — a history which, in the 

 case of the well-known long notes of the bird , is occasionally 

 traversed at the present time. A little call-note, " tewy," 

 is sometimes produced several times in succession, each 

 note more prolonged than the last, until the strain ends in 

 the ordinary long notes in all their sweetness. 



The origin of certain prolonged strains may also be 

 indicated in the cries of young birds. The nightingale, 

 for instance, has a harsh " sisisisisi " which is quite unlike 

 its sweeter tones. The fledged young one, however, when 

 being fed, utters a similar long rapid cry. The ordinary 

 cry of the young is a croak similar to that of the parents. 



The young greenfinch, ready to quit the nest, utters 

 when being fed, a rattling cry so like the " didititit " rattle 

 in the song of the parent that the only point of distinction 

 is that the parent gives the strain in several keys, and 

 interrupts it with other cries. The actual rattle is identical 

 with that of the young. 



The young fledged nuthatch, when being fed, utters a 

 quick repetition of an almost toneless cry, with the same 

 general character, however, as the full, bubbling, song- 

 rattle of the adult. 



It would, therefore, seem that when some song birds are 

 developing their strains by simple repetitions of cries, they 

 may be less inventive than at first appears, and be merely 

 returning to an infantile mode of expressing a want. 



The following note may be of interest as indicating that 

 a bird whose habitat is remote from the range of our 

 nightingale has followed a similar method in developing a 

 song. The British birds have a rather short strain consisting 

 of three or four peeting notes given at the same pitch, and an 

 ensuing full rattling sound at a lower pitch, the whole sound- 

 ing something like a " pee pee pee boblobloble." This is 

 given throughout the season of song, though it is one of 

 the least noticeable of the usual strains. It is varied in 

 length of repetition very slightly, but is rendered in any 

 interval of pitch between a third and an octave. Three 



years ago in Vancouver City, I was much struck with the 

 song of a common bush-warbler, a bird with the general 

 appearance and manners of our hedgesparrow. The bird 

 gave this strain of our nightingale perfectly, except that 

 the leading notes seemed to be very slightly inflected. 



The strain was in all other respects the strain of our 

 nightingale, pure and simple. It seemed never to be 

 modulated by the Canadian bird ; and it was particularly 

 noticeable as being almost the only bird-song to be heard. 

 But so frequent was it that the canaries on the houses near 

 vacant " lots " had all" caught " the song, and included it in 

 their own strains, and so accurately, that often I should 

 not have known which bird was singing had not the sound 

 come from some lofty window and not from the low 

 bushes. I doubt not but that many of the canaries in 

 Vancouver still have this strain, and that any local 

 observer who has noticed the song of the warbler could 

 confirm my statement as to the canaries. Did the 

 Canadian bird borrow it from our nightingale or rice versa ? 

 Or did they, uninfluenced by each other, follow the same 

 course in elaborating their strains from simple originals ? 



THE KARKINOKOSM, OR WORLD OF 

 CRUSTACEA.-V. 



By the Rev. Thomas R. R. Stebbing, m.a., f.r.s., f.l.s. 



THERE are many contrivances for moving through 

 water, but, few if any, are more handy than 

 rowing. Independently of any boat or implement 

 the human swimmer rows with his front legs, 

 commonly called his hands and arms. Birds, 

 beasts, fishes, insects, and crustaceans use various 

 appendages for the same purpose, and many of them might 

 with more or less propriety be called oar-footed. Among 

 crabs the genus Ermipes has monopolized the title in its 

 Latin form. In a Greek dress it falls to the Podocopa, a 

 division of the bivalved Ostracoda. But more suitably, in 

 another Greek derivative, it has been bestowed upon that 

 extensive branch of the Entomostraca, which are therefore 

 known as the Copcpoda. These oar-footed crustaceans, 

 individually considered, are a feeble folk, but in the mass 

 much worthy of respect. Unlike their little boxed-up 

 brethren the Ostracoda, they cannotproduce an interminable 

 list of fossils, or claim an unbroken record of representation 

 throughout the entire series of stratified rocks, to prove 

 the antiquity of their lineage. In this kind of documentary 

 evidence they are singularly deficient. But when regard 

 is paid to their extensive distribution, resourcefulness, 

 variety of structure, beauty of form and colouring, and 

 their indirect usefulness to mankind, they are found to 

 occupy no undistinguished place in the realm of existing life. 

 Of some of this order there are said to be thirty genera- 

 tions in three weeks. Such prolific accumulation may 

 seem incredible, but it harmonizes with the fact, repeatedly 

 recorded, of ships traversing miles of ocean coloured in 

 broad bands by dense masses of these small creatures. 

 Dr. G. S. Brady says, " There can be no manner of doubt 

 that the sea, from the Equator to the Poles, supports every- 

 where a profusion of Entomostracan life, chiefly of the order 

 Copepoda," and Sir John Murray, of the L'liaUenffer 

 Expedition, declares that " Copepoda were rarely, if ever, 

 absent from the tow-net gatherings when examined on 

 board ship," although the profusion was too great to admit 

 of more than a selection being preserved. Dr. Giesbrecht 

 describes a sort of fine drizzling rain that may sometimes 

 be seen close to the smooth surface of the Mediterranean. 

 It is a shrimpy shower, not from above, but from below. 

 There are swarms of certain Copepoda at the surface, and 



