render this explanation extremely probable. 

 With respect to the habit of the granivorous 

 birds, particularly the gailinaceae and ostriches, 

 of swallowing sand and small pebbles, it has been 

 hitherto attributed to an instinctive desire of 

 accelerating the trituration of the aliments in 

 a muscular and thick stomach. 



We have seen above, that tribes of Negroes 

 on the Gambia mingle clay with their rice ; some 

 families of Otomacs had perhaps formerly the 

 custom of causing maize and other farinaceous 

 seeds to rot in their poya, in order to eat earth 

 and amylaceous matter together : perhaps it was 

 a preparation of this kind, that father Gumilla 

 described confusedly in the first volume of his 

 work, when he affirms, cc that the Guamoes and 

 the Otomacs feed upon earth only because it is 

 impregnated with the sustancia del maiz, and the 

 fat of the cayman." I have already observed 

 above, that neither the present missionary of 

 Uruana, nor Fray Juan Gonzales, who lived 

 long in those countries, knew any thing of this 

 mixture of animal and vegetable substances with 

 the poya. Perhaps father Gumilla has con- 

 founded the preparation of the earth, which the 

 natives swallow, with the custom they still re- 

 tain (of which Mr. Bonpland acquired the cer- 

 tainty on the spot) of burying in the ground the 

 beans of a species of mimosaceae*, to cause them 



* Of the group of ingas. 

 VOL. V. 2 u 



