227 [Jackson. 



Grass Valley, California, the richest quartz gold mining district of the 

 State. Some days were spent at the gold mines of this town, and full 

 examinations were made of the mills, and process employed in the 

 extraction of the gold. We found Platner's chlorine process for 

 extracting gold from poor ores, was used in working the auriferous 

 pyrites concentrated from the taihngs of the amalgamating mills. The 

 village of Grass Valley is very beautiful, most of the cottages being 

 surrounded with flowers ; and the climate being very salubrious, people 

 of leisure and taste are attracted to the spot, and the good hotels of the 

 town are well patronized. 



On the 4th of June, I made an examination of the acorns which the 

 California red-headed woodpecker so abundantly inserts into holes 

 made in the bark of the trees. Knowing that the bird is insectivo- 

 rous I did not believe the common opinion that the acorns were eaten 

 by woodpeckers. The acorns are always driven into the holes made 

 to fit them, cup end foremost, so that the pointed end only is exposed 

 to view. They are packed in so tightly that it is difficult to extract 

 them without the aid of a knife. On getting out some of these acorns 

 I found in them only the worm, which had eaten up the kernel of the 

 nut. Thus it would appear that the woodpecker is able to select the 

 infected acorn in which there is a minute and almost invisible egg and 

 puts the acorn into a hole in such a manner as to prevent the escape 

 of the worm when it comes to maturity ; as the worm can only cut 

 through the softer portion of the shell at its base and not through the 

 hard pointed end, so it is securely imprisoned until the woodpecker 

 calls for it. Shice there must be a limit in time as to the procuring 

 of the infected acorns, and to the existence of the worms in the nuts, 

 and a sudden harvest of the worms would be obtained at a particular 

 time in the year, it seems probable that these birds lay up this store of 

 food for their young, which must require a large supply of animal food, 

 for it has been shown by Dr. Treadwell that a young robin eats about 

 its weight of worms per diem. 



Although woodpeckei-s are not gregarious, living in pairs and not in 

 flocks, they in this case, from necessity, have to act on community 

 principles, for it would be difficult for any one of the birds to identify 

 and defend his particular property, and the worm harvest must be 

 open to the whole community. Here, then, we have a fine example 

 of instructive prevoyance in birds and of provision made for their 

 young. Every year millions of acorns are nicely packed into holes in 

 the bark of trees and even in the wooden ceilings of the porticos of 

 houses, where a crack enlarged is made capable of receiving an acorn. 

 A lady told me that every morning during the acorn season it seemed 

 as if a hundred carpentei-s were at work hammering in the veranda of 

 her house, so loud were the strokes of the woodpecker's beak. 



