466 



SCIENCE. 



IN. S. Vol. XX. No. 510. 



ness. Nevertheless, the probability of such 

 conceptions having had real counterparts in 

 the material world is absolutely nil, so far as 

 experience shows, and for like reason we can 

 ascribe only a mythical existence in times 

 past to warm-blooded reptiles, feathered 

 reptiles, or reptiles possessing so eminently 

 bird-like a characteristic as the gizzard. 



It is, therefore, surprising to find a writer ■ 

 in Science (No. 501, p. 185) advancing the 

 anomalous conception of reptiles with organs 

 corresponding to the avian gizzard. The 

 solitary fact upon which Mr. Barnum Brown 

 bases his conclusion is the discovery, in a 

 number of instances, of small-sized silicious 

 pebbles in association with plesiosaur skeletons 

 from the western Cretaceous. Certain corol- 

 lary assumptions, apparently accepted as axio- 

 matic by Mr. Brown, but nevertheless debat- 

 able, may be stated as follows : 



(1) These ' stomach stones ' were contained 

 within the alimentary canal prior to the death 

 of the creatures, and not accidentally deposited 

 upon or with their remains. (2) The stones 

 were intentionally swallowed, and not taken 

 promiscuously with other fare, as might 

 happen in bottom-feeding. (3) They served 

 as a mechanical aid to digestion through the 

 intervention of a supposititious gizzard-like 

 organ. (4) Thin-shelled prey like cephalopods 

 could not have been crushed upon one an- 

 other without the admixture of a judicious 

 quantity of ' stomach stones.' (5) The non- 

 occurrence of such stones amongst European 

 reptiles proves only that the latter ' had no 

 stomach ' for them, not that they were giz- 

 zardless. (6) The history of the gizzard 

 (horresco referens) shows that it was de- 

 veloped first amongst cold-blooded vertebrates, 

 then lost by them, and afterwards independ- 

 ently acquired by birds. Incidentally it ap- 

 pears that plesiosaurs possessed the most 

 highly specialized digestive apparatus known 

 amongst reptiles, ancient or modem. 



For our part, begging pardon of Mr. Brown, 

 we are willing to consign to birds the exclusive 

 eniojrment of gizzards and feathers. A 

 cogent reason for suspending judgment as to 

 the function of ' stomach stones ' is found in 

 their limited distribution. Before asking us 



to believe that all plesiosaurs had ' gizzard- 

 like arangements ' (sic), let it be shown that 

 all plesiosaurs and related reptiles had the 

 habit of gorging themselves with foreign mat- 

 ter to the extent asserted of American species, 

 and let no doubt remain that these pebbles are 

 not of adventitious origin. 



C. E. Eastman. 

 Harvard Univeesity. 



To THE Editor of Science: In Science for 

 August 5, 1904, at page 184, mention is made 

 of the stones often found apparently in the 

 stomachs of fossil plesiosaurs, with the sug- 

 gestion that they may be connected with the 

 food habits of the animals with whose remains 

 they are associated. It is of interest to notice 

 that, according to Mr. Hornaday, the stomachs 

 of the west coast sea lions contain rounded 

 pebbles an inch or two in diameter. As their 

 food seems to be somewhat similar to that 

 of the extinct plesiosaurs, a careful study of 

 the sea lion's habits may be of importance to 

 paleontology. Julius Henderson. 



SPECIAL ARTICLES. 

 determination of longitude. 



The recent determination of the difference 

 of longitude between San Francisco and 

 Manila by the use of the cables of the Com- 

 mercial Pacific Cable Company, by the Coast 

 and Geodetic Survey completed the longitude 

 girdle of the earth, and the results will be 

 published in detail in the ' Eeport of the 

 Superintendent of the Coast and Geodetic 

 Survey,' for 1904. In anticipation of that 

 report the results are now made public by the 

 authority from the superintendent. 



The parties in charge of Assistants Edwin 

 Smith and Ereemont Morse started for the 

 field in March, 1903, and finally completed the 

 field work in May, 1904. The distance by cable 

 from San Erancisco to Manila (7,84Y nautical 

 miles) is covered by four cables extending 

 from San Erancisco to Honolulu, Honolulu 

 to Midway Island, Midway Island to Guam 

 Island and Guam Island to Manila. For the 

 purpose of exchanging time signals, the Com- 

 mercial Pacific Cable Company very generously 

 gave the use of the cables to the survey free of 

 charge and at all the stations extended to the 



