Dec. 5, 1878] 



NATURE 



lOI 



seen, and it has been the good fortune of Alexander 

 Agassiz to succeed in hatching the eggs and raising the 

 young until they showed at least the principal structural 

 pecidiarities of the adult. A short account of the chief 

 facts in connection with this stage of the bony pike's 

 history- will appear in the forthcoming number of the Pro- 

 ceedings of the American Academy of Arts and Sciences ; 

 from an advance copy we cull the following details : — 

 The spawning-ground selected for observation was the 

 Black Lake, at Ogdensburgh, N.Y. Mr. Garman, who 

 •describes the scene, and Mr. Blodgett, who rendered most 

 essential assistance, deserve the thanks of every naturaUst. 

 The eggs collected were carried by the hand in pails from 

 Ogdensburgh to Cambridge, where their progress was 

 watched by Prof, A. Agassiz. 



The fish began to spawn about May 18. Little pro- 

 jections of granite stand out here and there into the lake. 

 The frosts from time to time have broken off from these, 

 small angular blocks, which lie piled together under the 

 water at depths varying from two to fourteen inches. Into 

 these shallows the female fish would come, each of them 

 attended by two males. While very timid when in deep 

 water, they seemed to be courageous to recklessness 

 when they approached the shallows. On they would 

 come in threes, when rising to the surface of the 

 water, and thrusting their bill out of it they would open 

 this widely, then take in air, and close it with a snap. 

 In some few cases three or four males would be in 

 attendance on one female, but much more often there 

 would be but two, and these would swim resting on either 

 side of the female fish, their bills reaching up toward the 

 back of her head. At times the water would be lashed 

 into all directions with their conjoined convtilsive move- 

 ments. The eggs when laid were excessively sticky ; to 

 whatever they happened to touch they stuck, and so tena- 

 •ciously, that it wan next to impossible to release them 

 without tearing away a portion of their envelopes. It is 

 remarkable that, as far as could be seen, there was, on 

 and about the spawning ground, a complete absence of 

 anything that might ser\'e as food for the young fish. 



Of the quantity of eggs brought to Cambridge, only 

 thirty hatched, and not one of those artificially fecundated 

 was hatched. In Prof. A. Agassiz' anxiety not to spoil 

 this interesting experiment he did not venture to exa- 

 mine any of the fresh eggs ; so that the history of their 

 segmentation and very early development remains to be 

 worked out. The envelope of the eggs is very opaque 

 and of a yellowish green, like that of toads. Of the 

 thirty hatched out by the end of May, twenty-eight were 

 ahve in the middle of July last. When first hatched the 

 young fish possesses a gigantic yolk-bag, and the pos- 

 terior part of the body presented nothing specially differ- 

 ent from the general appearance of any ordinary bony 

 ^teleostean) fish of the same age ; but the anterior part 

 was most extraordinary : it looked hke a huge mouth 

 cavity, extending nearly to the gill opening, and crowned 

 by a depression like a horse's hoof in outline, along the 

 margin of which were a row of protuberances acting as 

 suckers. The moment the young fish was hatched it 

 attached itself to the sides of the vessel by means of these, 

 andwouldhangimmovable. The eyewas not very- advanced, 

 the body was transparent, the gill covers were pressed 

 against the sides of the body ; the tail was slightly 

 rounded, the embryonic fin is narrow, and there were no 

 traces of embryonic fin rays ; the olfactory lobes were 

 greatly developed and elongated as in sharks and skates ; 

 the chorda was straight. On the third day the body 

 became covered with minute black pigment cells, and 

 then was noted the first traces of the pectoral fins, and 

 the snout became more elongated; the great yolk-bag 

 was greatly reduced in size. About the fifth day were 

 seen traces of the caudal, dorsal, and anal fins. Gra- 

 dually the snout became elongated, the suckers concen- 

 trated, and the disproportionate size of the sucking disc 



became reduced, so that when about three weeks old it 

 became altogether more fish-like. The sucking disc was 

 now reduced to a swelling at the top of the upper jaw, 

 the yolk-bag had disappeared, the gill covers extended well 

 up to the base of the pectorals — these latter were in constant 

 motion, and thetail exhibited thesame rapid vibratile move- 

 ments. Theyoungfishnowbeginstoswimabout,andis not 

 so dependent upon its sucking disc, and at last this only 

 remains as a fleshy globular termination on the snout. 

 At this stage, too, the young have the peculiar habit of 

 the adult fish of coming to the surface to swallow air. 

 When they go through the process imder water of ex- 

 piring this air they open their jaws wide and spread their 

 gill-cover, and swallow as if they were choking, making 

 violent efforts, until a minute bubble of air has become 

 liberated, when they become quiet again. Their growth 

 is rapid. Within a month the teeth made their appear- 

 ance, and some of the fin-rays on the fringe of the 

 pectorals were to be seen. 



Prof. A. Agassiz draws the following conclusions from 

 these observations: — "That notwithstanding its similarity 

 in certain stages of its growth to the sturgeon, notwith- 

 standing its affinity with sharks by the formation of its 

 pectorals from a lateral fold, as well as by the mode of 

 growth of the gill openings and gill arches, the Lepi- 

 dosteus is not at all so far remored as is generally 

 supposed from the bony fishes." The memoir is illus- 

 trated by five plates containing some forty-five figures, 

 and is only to be regarded as a preliminary account, but 

 it is a preliminary account of such exactness, importance, 

 and interest, that no apology is necessary for bringing it 

 at once under the notice of our readers. This memoir 

 was presented to the American Academy as recently as 

 October 8 last. E. Perceval Wright 



i THE MUSIC OF COLOUR AND MOTION 



AT the Physical Society, on November 23, 1878, Prof. 

 . W. E. Ayrton, late of the Imperial Engineering 



; College, Tokio, Japan, read a paper, written by himself 

 I and Prof. J. Perry, of the same college, on "The Music 

 j of Colour and of Visible Motion." The authors began 

 ; by pointing out the well-known fact that emotion is ex- 

 i cited by moving bodies, and they believed that, upon this 

 ! basis, a new emotional art would be created which would 

 receive a high development in the far distant future. All 

 methods of exciting emotion could be cultivated ; but of 

 these, music, by reason of the facility with which its 

 effects could be produced, had alone been highly perfected 

 by the bulk of mankind. Sculpture and painting are not 

 purely emotional arts, like music, inasmuch as they in- 

 volve thought. It would take a long time and much 

 culture for the eye to behold moving figures with similar 

 emotional results to those of the ear on hearing sweet 

 sounds ; but time and culture only might be necessary. 

 It might be due to their neglect of this emotional ten- 

 dency that the Western nations felt little emotion at 

 moving visual displays. For among the Eastern nations 

 they had entertainments consisting of motions and dumb 

 show, which, although incomprehensible and even ludi- 

 crous to the European, powerfully affected the feelings 

 of a native audience. In Japan the authors had seen 

 whole operas of "melodious motion" performed in the 

 theatres, the emotions being expressed by movements of 

 the body, affecting to the audience, which were quite 

 strange to them. The accompanying orchestral music 

 was, withal, displeasing to the authors, while, on the 

 other hand, Western music is mostly displeasing to the 

 Japanese. 



The emotions produced by rapidly-moving masses, 

 such as a train bowling up to a bridge, or by changing 

 colours, as in sunsets, have been felt by all, and those 

 excited when the moving bodies are very large do not 



