March 15, 1918] 



SCIENCE 



269 



to their present condition of domestication. In 

 the opinion of the present writer, who is now 

 in Peru and who has lately been in Bolivia as 

 well, this argument is of slight, if any, value. 

 From close study of the matter it becomes 

 clear that the llama is only partially domes- 

 ticated. There are several criteria of domes- 

 tication : If an animal depends upon a man for 

 its food, if it breeds while in captivit.y, if it 

 needs to be artificially sheltered from the stress 

 of weather, if it is obedient to the wishes of 

 its owner, it may be said to be domesticated. 

 It is quite certain that by far the greater 

 part of the llama species to-day feed them- 

 selves, refuse to breed in captivity (or, at any 

 rate, generally breed when as far as possible 

 from man), and do without shelter. It is true 

 that the llama is more or less obedient to its 

 owner, but it is a docile animal by nature, 

 and, so long as it is not overloaded, it is a 

 ready worker in its own way. Since this 

 is so, it is quite clear that the llama is only 

 partially domesticated, or rather, that it has 

 been partially subjected to the uses of man, 

 and it is certain that its status does not imply 

 any long period of human influence. 



Philip Ainsworth Means 

 Lima, Pebu, 



November 29, 1917 



THE ORIGIN OF THE CUSTOM OF TEA 

 DRINKING IN CHINA 



To THE Editor of Science: I have been 

 much interested in a statement which occurs 

 in the late Professor King's book " Farmers 

 of Forty Centuries " relative to the origin of 

 the custom of tea drinking in the Orient. 

 Professor King states (p. 77) : 



In a sampan managed by a woman and her 

 daughter, who took us ashore, the middle section of 

 the boat was furnished in the manner of a tiny 

 sitting-room, and on the sideboard sat the com- 

 plete embodiment of our fireless cookers, keeping 

 boiled water hot for making tea. This device and 

 the custom are here centuries old and throughout 

 these countries boiled water, as tea, is the universal 

 drink, adopted no doubt as a preventive measure 

 against typhoid fever and allied diseases. 



And (p. 323) : 



The cultivation of tea in China and Japan is 

 another of the great industries of these nations, 

 taking rank with that of sericulture, if not above 

 it, in the important part it plays in the welfare of 

 the people. There is little reason to doubt that 

 the industry has its foundation in the need of 

 something to render boiled water palatable for 

 drinking purposes. The drinking of boiled water 

 has been universally adopted in these countries as 

 an individually available, thoroughly efficient and 

 safe guard against that class of deadly disease 

 germs which it has been almost impossible to ex- 

 clude from the drinking water of any densely 

 peopled country. 



These statements would indicate the fol- 

 lowing sequence of events : (1) the pollution 

 of the drinking water, (2) disease arising 

 from this pollution, (3) boiling of the drink- 

 ing water to prevent disease, (4) addition of 

 tea leaves to mask the insipid taste of the 

 boiled water. While I have no doubt but 

 that the first two items occurred in the order 

 given, I have very grave doubts as to the 

 sequence of the third and fourth items. It 

 is extremely improbable that it was recognized 

 centuries ago that typhoid fever, etc., were 

 disseminated by pollution of the water supply, 

 especially inasmuch as there was no knowl- 

 edge of microorganisms or of the role which 

 they play in disease until the work of Pasteur 

 (1857-1863). Undoubtedly disease with the 

 Chinese, as with every other people, was early 

 regarded as the act of demons or a visitation 

 of the gods. 



To my mind, cause and effect were some- 

 what as follows: (1) The drinking water was 

 undoubtedly polluted and typhoid, cholera, 

 dysentery, etc., were endemic. (2) Certain 

 families or clans found that a pleasing bever- 

 age could be made by steeping the leaves of 

 the tea plant in hot water with the result 

 that they drank very little if any of the pol- 

 luted waters without previously boiling it. (3) 

 Their neighbors or neighboring communities 

 observed that these families or clans who 

 drank tea had relatively little disease as com- 

 pared with the non-tea drinkers and as a 

 result the custom of tea drinking spread 



