376 



SCIENCE. 



[N. S. Vol. XXII. No. 560. 



is longer than that of Brontosaurus, the ab- 

 sence of limbs in the whale would reduce 

 the water displacement and weight. 



Several new features are brought out in re- 

 lation to the proportions of Brontosaurus. 

 While a number of terminal vertebras are un- 

 doubtedly missing, the tail is less elongate and 

 massive than was supposed by the writer at 

 one time. There is no evidence that it served 

 for the support of the body, nor was the fin 

 development for propulsion in water so great 

 as in Diplodocus. A second point of interest 

 is that the sacrum, while the center for motion, 

 was not certainly the highest point in the 

 body, as at one time supposed by the writer. 

 The center of the vertebrae arch upward in 

 front of the sacrum, and while the neural 

 spines rapidly subside, the highest point ap- 

 pears to have been about the raiddle of the 

 back ; unless, indeed, the fore limbs were very 

 much more flexed than appear in the present 

 mount. 



There is still room for wide differences of 

 opinion as regards the habits and means of 

 locomotion of these gigantic animals. Some 

 hold the opinion that the limbs were far more 

 flexed at the knee and elbow than they are in 

 the present mount, that on land at least the 

 animal had rather the attitude of the alligator, 

 and that only while submerged beneath the 

 water were the limbs straightened for the pur- 

 poses of walking along the bottom, the claws 

 serving to keep the feet from slipping in the 

 mud. H. F. O. 



THE DRUMMING OF THE DRUM-FISHES 

 (sCIiENID.E). 



It is rather remarkable that so conmaon a 

 function as the drumming of fishes should 

 have remained so long misunderstood; that so 

 much speculation should have been indulged 

 in regarding a phenomenon so easily investi- 

 gated in most parts of the world; and that a 

 conspicuous specialized drumming muscle 

 should have been either overlooked or ignored 

 by ichthyologists. 



For several years, as opportunity was af- 

 forded, T have been studying the peculiar 

 drumming sounds made by those fishes in 

 which this function is so strikingly developed 



that it has determined the family name, the 

 inquiries being in continuation of some ob- 

 servations and experiments on the squeteague 

 (Cynoscion regalis) carried on by Professor 

 E. W. Tower, at Woods Hole, in 1901 and 

 1902, and noted by me in the Report of the 

 U. S. Fish Commissioner for 1902 (page 137). 



The diverse notions prevailing among 

 modern writers on fishes may be seen from the 

 following quotations from a few standard 

 works. 



Giinther, in ' An Introduction to the Study 

 of Fishes ' (1880), makes only a single refer- 

 ence to drumming, and that a highly edifying 

 one in connection with Pogonias cromis: 



These drumming sounds are frequently noticed 

 by persons in vessels lying at anchor on the coasts 

 of the United States. It is still a matter of un- 

 certainty by what means the drum produces the 

 sounds. Some naturalists believe that it is 

 caused by the clapping together of the pharyngeal 

 teeth, which are very large molar teeth. How- 

 ever, if it be true that the sounds are accompanied 

 by a tremulous motion of the vessel, it seems tnore 

 probable that they are produced by the fishes 

 beating their tails against the bottom of the 

 vessel in order to get rid of the parasites with 

 which that part of their body is infested. 



Jordan and Evermann, in their admirable 

 ' Amei'ican Food and Game Fishes ' (1902), 

 reassert . what was stated in their ' Fishes of 

 North and Middle America ' (1898), namely, 

 that the peculiar noise is ' supposed to be pro- 

 duced by forcing air from the air-bladder into 

 one of the lateral horns.' 



Boulenger, in the section on fishes in volume 

 VII. of the Cambridge Natural History^ 

 (1904), discusses ' sound-producing organs ' at 

 some length, but appears to be unaware of 

 the special mechanism existing in the drum- 

 fishes. He cites several ways in which sounds 

 are produced through the agency of muscles 

 connected with the air-bladder, and copies 

 from Sorensen" a diagram of the air-bladder 

 and ' musculo-tendinous extensions from mus- 

 cles of the body-wall ' of a croaker (Micropogon 



^ Reviewed by Dr. Theodore Gill in Science, 

 April 28, 1905. 



- Journal of Anatomy and Physiology, Vol. 

 XXIX., 1895. 



