288 POPULAR GEOGRAPHY OF PLANTS. 



of great perplexity, since, so far as we can make out, no 

 cows, or any other animals, are at all concerned in its pro- 

 duction. Being determined to clear up the mystery, we 

 resolve to watch the proceedings of these natives ; and the 

 next time they appear with their empty pails we follow at 

 a little distance, till, to our still greater perplexity, they 

 begin to collect round particular trees, in the bark of which 

 they proceed to inflict deep gashes, from which, to our no 

 little surprise, the milk pours forth into the pails. 



And now the conviction darts through us that these must 

 of course be the curious Cow-trees (Galactodendrum utile) 

 of which we have so often heard, allied to the Nettle family; 

 in South America they go by the name of Palo de Yaca. 

 As Humboldt tells us, these trees appear to be peculiar to 

 this locality; the Andes hereabouts lie between 8 and 10 

 north latitude. The milk has "an agreeable taste and 

 aromatic smell ; it is glutinous, tolerably thick, and desti- 

 tute of all acrimony." Cheese also, or at least "a sub- 

 stance resembling it, forms on the surface when exposed 

 to the air." 



Having crossed the summit of that chain of the Andes 

 nearest the coast, vast plains (here called punas] break on 

 our view, the level of which is often higher than the tops of 



