URDUCKA] PHYSIOLOGICAL AND MEDICAL OBSERVATIONS 173 



on the nature, quantity, and place of introduction of the poison. 

 Bites of the Gila monster, tarantula, and centiped, although much 

 spoken of, are very rare and are probably never fatal. Intestinal 

 parasites are heard of but seldom. 



The harmful plants of the region covered include, besides such 

 vegetable poisons as aconite, datura, etc., and poisonous fungi, species 

 that act only on some whites, as well as on some Indians, in a manner 

 similar to poison ivy or sumac; and there are also plants that act, 

 only on a somewhat prolonged contact with the skin, like canthari- 

 des (vesicants). Of these plants the only ones that were occa- 

 sionally heard of as having caused harm to anyone, without being 

 administered as medicine or poison, were those that act by contact, 

 principally species of Rhus. The Indians are sufficiently acquainted 

 with the qualities of many of the harmful plants to avoid them. 

 Tobacco is cultivated by some of the Mexican tribes (e. g., the Tf.ra- 

 huniare) and grows wild elsewhere (e. g., in the Otonii region, 

 Hidalgo) , it is smoked by the men in all the tribes, but ao where to 

 excess. The preferred way of using it is in the form of cigarettes, 

 made usually of a little tobacco and much corn husk. It is probably 

 never the cause of any sickness. A species of datura is occasionally 

 added to tesvino by the White Mountain Apache, and in another 

 form is said to be used by the Walapai and the Zufii. Peyote is 

 taken among most of the Mexican tribes, above all by the Huichol, 

 and also to a slight extent by the Papago and Pima. Nothing 

 apparently is known by the Indians visited of the use of any other 

 narcotic plants. 



The dry season throughout is, naturally, the more healthful one. 

 The diseases that develop during this season comprise milder forms 

 of malaria, or calentura, numerous cases of ophthalmia induced mainly 

 by flying sand, and in the colder localities a moderate number of 

 affections of the bronchial system, lungs, and pleura. During the wet 

 season malarial disorders become prevalent and more dangerous. 

 Their frequency and gravity increase from the north southward ; they 

 are particularly serious along the lower stretches of the Pacific coast. 

 Epidemics are more common and fatal during the rainy season, and 

 the same is true of arthritic troubles and of gastro-intestinal disorders 

 in adults and particularly in infants. On the whole, the rainy season 

 is the period of danger to health and one of increased mortality. 



Jrregular meals, imperfect preparation of food, and the nature of 

 some of it, as the apparently much relished unripe fruit, give rise to 

 frequent gastro-intestinal disturbances. 



Excesses in food and especially in drink, where they occur, are 

 quite as prolific sources of digestive disorders as they are in whites, 

 but serious consequences of either are met with but seldom. The 

 Indian drinks readily to excess on all favorable occasions, and yet 



