May 10, 1918] 



SCIENCE 



461 



light near the convergent to arrange itself in 

 the form of an hyperbola, but no definiteness 

 in the position of the axes could be detected 

 other than a tendency for the visible hyperbola 

 to occupy a quadrant opening toward the north 

 or nortlieast. At many times during the hour 

 the auroral display covered large sections of 

 the southern sky, and the ^vTiter can remember 

 thinking of the peculiar lateral shifting of the 

 curtain in certain auroras and wondering how 

 this would look if it took place near the con- 

 vergent, but saw no such movement. At times 

 a shaft of light more or less meridional in 

 direction lay across the convergent. 



At the time the writer hoped that others 

 were making similar observations and that it 

 might be possible to determine the height of 

 the point of convergence and he was somewhat 

 surprised later to realize that his observations 

 indicated the further fact of a change in the 

 position of the convergent with reference to 

 the stars which seemed only partly to be ex- 

 plained by their rotation. He only hopes that 

 similar observations were made by others in 

 diflFerent places and that the ones herein re- 

 corded are sufficiently accurate to make them 

 of value. They at least have the merit of 

 having been made by one who had no precon- 

 ceived idea of what they might indicate, and 

 who regrets, if they prove to have value, that 

 he was unable to make use of more exact tools. 



Lancaster D. Burling 

 Geological Scrvet, 

 Ottawa, Canada 



THE DOMESTICATION OF THE LLAMA 



To THE Editor of Science: A note in 

 Science for March 15, 1918, by Mr. Philip 

 Ainsworth Means, leads the reader to believe 

 that the llama, alpaca, vicu3a, and guanaco are 

 distinct species and that the common belief is 

 that all have been domesticated to some degree. 



Prior to about 1890 there was great confu- 

 sion regarding the specific status of these four 

 animals, though the prevailing theory was that 

 the llama had been derived from the guanaco 

 and the alpaca from the vicuna. It is now 

 known that the vicuna has never been domesti- 

 cated, and that the alpaca and the llama are 



both domesticated forms of the wild guanaco.* 

 In view of the conspicuous differences between 

 these two tame races of the guanaco it is easy 

 to believe that a very long period of actual 

 domestication has obtained, for the alpaca has 

 been bred for his wool and the llama has been 

 developed as a beast of burden as effectually 

 as any of our races of domestic animals have 

 been produced for special purposes by the most 

 careful selective breeding. 



The llama and the alpaca are not known in 

 a wild state, though they of course occur, as 

 do almost all other domesticated species, in a 

 semi-wild or feral condition. They represent 

 one of the rare cases of true domestication of 

 an animal, and one of the still rarer cases 

 where the ancestral species is known and still 

 exists as a wild creature. Contrary to the 

 statement in Science, they do breed freely in 

 confinement; but since so many wild animals 

 propagate regularly in captivity this can 

 hardly be considered a test of true domesti- 

 cation. N. Hollister 



National Zoological Park, 

 Washington, D. C, 



the audibility op sound 

 Eeplyinc. to the suggestion of Mr. Willard 

 J. Fisher, in your issue of April 2G, that an 

 investigation be made of the area about Hali- 

 fax with regard to audibility of the sound from 

 the great explosion there, it may interest you 

 to know that such an investigation was under- 

 taken by the National Geographic Society 

 not long after the occurrence of the explosion 

 and that a quantity of data has been accumu- 

 lated which is to be charted and tabulated as 

 soon as other work will permit. 



Charles E. Munroe 



SCIENTIFIC BOOKS 



The American Indian. An Introduction to 

 the Anthropology of the New World. By 

 Clark Wissler, Curator of Anthropology in 

 the American Museum of Natural History, 

 New York City. New York, 1917. Pp. 

 xiii, 435. 

 1 Thomas, Proc. Zool. Soc. London, 1891, pp. 



B85-387. 



