SOME OBSERVATIONS ON GUINEA-PIGS IN PERU. 



On a midsummer day in December 1911 I arrived as a guest at the 

 Harvard College Observatory in Arequipa, Peru, where I went in 

 search of guinea-pigs, wild and domesticated, to be used in breeding 

 experiments. 



The day after my arrival at the observatory I walked a short dis- 

 tance up the highway through a group of adobe cabins, straw-thatched 

 and without chimney or windows, and with a single door. On looking 

 in at the open door of one of the cabins, I was pleased to see a domesti- 

 cated guinea-pig of the common spotted black-and-white sort familiar 

 to lovers of pet-stock throughout the world. In other near-by cabins 

 I found considerable numbers of guinea-pigs were kept, in one as many 

 as 40. They were fed on fresh-cut alfalfa or the green leaves of maize, 

 receiving apparently no other food and no water. At the back or 

 sides of the cabin was a sort of shelf or bench of stone used as a seat 

 or couch, underneath which the guinea-pigs had their home. Their 

 escape through the open door was prevented by a high lintel of stone, 

 perhaps 15 inches (38 cm.) high, over which one has to step in entering. 

 In these cabins were seen most of the common color varieties of guinea- 

 pigs known to us, agouti, black, yellow, and white (albino). None of 

 the colored individuals which I saw was self-colored; all were spotted 

 with white or with yellow or in both ways. The same predilection for 

 spotting is seen in the other important native domesticated animal, the 

 llama. I saw no llamas except such as were spotted; some were black 

 spotted with white, but the majority were of a soft shade of buff or 

 fawn spotted with white. The common spotted condition of our 

 guinea-pigs is undoubtedly one of long standing; indeed it would seem 

 that the Peruvian natives breed no other variety except such as are 

 either white spotted or all white. The unspotted or " self-colored " 

 varieties now kept by fanciers in Europe and America have probably 

 been produced by selection from stock originally spotted. This is 

 indicated by the great difficulty in securing a self-colored race entirely 

 free from spotted individuals. Most self-colored races, even when bred 

 for many generations from self-colored ancestors exclusively, will pro- 

 duce an occasional individual bearing a few hairs or a patch of hairs of 

 some other color, or of white. 



Among the guinea-pigs kept by the natives near Arequipa, I observed 

 an occasional animal having a rough or resetted coat. This variety is 

 known to fanciers in Europe and the United States under the name 

 Abyssinian. (See Castle, 1905.) It is said, on the authority of 

 Geoffrey Saint-Hilaire, to have been introduced from Peru into Europe 

 about the year 1872 in a rough-coated, long-haired individual received 

 at the Jardin d'Acclimatation, Paris. In conformity with this account 



5 



