June 29, 1883.] 



SCIENCE. 



603 



This is of interest in the study of cosmic develop- 

 ment. C. B. Wakbing. 

 Poughkeepsie, N.T., June 16, 1883. 



Flight of the flying-fish. 



The difficulties in the way of accurate observation 

 of the flying-flsU in motion arc numerous and real. 

 Seen always from above, usually at a distance which 

 is constantly increasing, and while the observer him- 

 self is in rapid motion, it is not strange that such con- 

 flicting opinions exist, or that the mode of flight is so 

 often spoken of as a mystery. 



During a trip by steamer from New York to Rio 

 Janeiro viO, the West Indies and ParS, and on the re- 

 turn trip coming directly from Rio to New York, I 

 watched flying-fish nearly every day, and frequently 

 all day, and satisfied myself on the following points : — 



Tlie fish usually leaps clear of the water at once, 

 leaving it commonly at an angle of 45° or less. After 

 leaving the water, no forward impulse whatever is re- 

 ceived (except sometimes from the wind) until the 

 water is again touched, when the tail may be used 

 effectively without immersion of the rest of the body. 

 Very soon after leaving the water, yet not instantly, 

 the pectorals are spread, and an instant later the 

 ventrals. 



Both sets of fins are kept quietly extended so far as 

 any voluntary vibration is concerned. Any similar, 

 tensely stretched membrane would quiver more or 

 less when cutting the air at such speed. 



Ordinarily the two pectorals lie in about the same 

 plane. They are never carried much below the 

 body, but are frequently lifted considerably above it, 

 especially when going before the wind, at which time 

 the whole fish rolls from side to side, precisely as 

 does a sailing-vessel under similar circumstances. 

 The course may be a simple curve, as it commonly is 

 in calm weather, or it may be undulating, as is usu- 

 ally the case in rough weather or over a heavy swell. 

 I think the ventrals are used to direct the fish up or 

 down, as they certainly work independently of the 

 pectorals, and closing them would naturally drop the 

 tail. Toward the close of the first stretch, and when 

 the fish wishes to re-enter the water, the pectorals 

 are instantly closed, and he shoots head foremost into 

 the water with only a slight splash. 



If, on the contrary, he wishes to continue in the 

 air, the long lower lobe of the tail is allowed to drop 

 into the water, and a few vigorous strokes send him 

 upward and forward, sometimes enabling him to clear 

 another hundred feet before repeating the action, 

 which I have seen him do at least seven or eight 

 times before finally entering the water for a fresh 

 start. 



Not unfrequently the tail is dropped, seemingly by 

 closing the ventrals, and an undulating motion so 

 obtained, even when there are no waves or swells to 

 be cleared ; and, although the tail may not then touch 

 the surface, it looks as if the fish were/eeKnr/ for the 

 water, which I think is really the case. The poetic 

 wetting of the wings in the crest of a wave so as to 

 prolong the flight appears to be a harmless bit of 

 imagination for all but the fish: to him it is disas- 

 trous. His tail alone needs wetting; and, when by 

 mistake he takes the top of a wave bodily, it usually 

 topples him over, or at least checks him noticeably. 

 The drying of the wings would be rather favorable 

 than otherwise. 



I was not able to detect any voluntary change of 

 direction to right or left while in the air. 



Once a large fish rose quite close to us, and started 

 directly toward the steamer. When within a few 

 yards, he suddenly closed his pectorals, plunged into 



the water, and almost instantly issued again in a 

 nearly opposite direction. 



Examination of a Pacific species in alcohol (and I 

 presuine the same general structure holds good for 

 the genus) shows that the pectorals are inserted at 

 such an angle with the axis of the body, that, if the 

 body be horizontal and in motion, the air striking on 

 their lower surfaces must tend to raise the fish, 

 although at the expense of a certain amount of for- 

 ward motion. Evidently, then, any beating of the 

 pectorals would only retard the fish still more, even 

 if it did support him somewhat in the air. The con- 

 clusion seems inevitable, however, that the tail alone 

 is the propeller, the other fins acting solely and pas- 

 sively as supporters. Walter B. Babbows. 



"Wesleyan university, Middletown, Conn. 



HEITZMANN'S MICROSCOPICAL 

 MORPHOLOGY. 



Microscopical morphology of the animal body in health 

 and disease. By C. Heitzmann, M.D. New 

 York, /. H. Vail §• Co., 1883. 19 + 849 p. 8°. 



Dr. Heitzmann, formerly' of Vienna, now of 

 New York, is well known as an unusually good 

 histological draughtsman. Ten years ago he 

 published some investigations on the minute 

 structure of protoplasm. To his own re- 

 searches on this subject he has long attributed 

 an importance which scientific men of much 

 greater experience and ability have failed to 

 recognize. The present volume, a very well 

 made and beautifully illustrated book, although 

 it comes in the guise of a manual of normal 

 and pathological histology, is obviously in- 

 tended principally to bring forward the author's 

 own theories, and to insist upon their funda- 

 mental character and great value. 



The author so openly implies his conviction 

 that he is a neglected grandeur, that he incites 

 the critic to a severity of comment that a tone 

 of modest}' more commensurate with the real 

 value of his researches would not have called 

 forth. The general defect of the book is want 

 of judgment on the author's part, and an exag- 

 gerated confidence in his own notions. Thus, 

 being unusually skilful with his fingers, he 

 scoffs at microtomes (p. 7), and closes a slur- 

 ring paragraph upon them with, " The greater 

 the complication, the less is the value of such 

 machines." A man who makes such a state- 

 ment without anj- limitation reveals a hopeless 

 lack of comprehension of the indispensable 

 requirements of many branches of histological 

 investigation. The second chapter in the book 

 discusses the general properties of living mat- 

 ter, and contains a number of characteristic 

 loose assertions: for instance, "Life is evi- 

 dently a peculiar kind of motion of the 

 molecules (plastidules) of living matter, of a 

 relatively short duration" (p. 14). This is 



