1 



BOTANY. 



mountains nearly 3,000 feet high, the depth of the well is 290 feet, though 

 with 150 feet of water on 31st July, 1867. At Nevada Station, six miles 

 distant and 129 feet lower, the well was 110 feet deep with but fifteen inches 

 of water at the same date. In Unionville Valley at Olive Ranch on Coyote 

 Creek, six miles east of the summit of Star Peak, a well was sunk 104 feet 

 through gravel without finding water. In Humboldt Valley east of the 

 Eugene Mountains and in the border of a large sandy plain covered by an 

 unusuallylarge growth of Artemisia a well was sunk to as great a depth but 

 without success. Not to multiply instances, it is at least frequently the case 

 that in the deposits which fill the valleys there are no strata of clay or rocks 

 to intercept and retain the water near the surface. 



To test therefore in a measure the ability of the most prevalent forms 

 of foliage to resist the absorbent power of the air, some experiments were 

 made by Mr. King's direction, with results as shown in the following table. 

 The specimen of Artemisia selected was young and vigorous, six years old, 

 the weight of the portion above ground being 24 ounces, or 776 grammes, 

 of which the woody portion weighed 384 grammes or nearly 50 per cent. 

 Of the remaining green stems and leaves, the leaves contributed 79 per cent, 

 or nearly 40 per cent, of the whole. Of Tetradymia canescens branches only 

 were taken. One specimen gave 35 per cent, of wood, 8 per cent, of the 

 previous years growth, and 57 per cent, of new shoots and leaves, and a 

 second specimen 53 per cent, of wood to 47 per cent, of young shoots. A 

 branch of a larger plant gave 150 grammes of young stems to 98 grammes of 

 wood, or over 60 per cent. Smaller branches of a more pubescent form gave 

 67 per pent., and in a second instance 60 per cent., of young twigs and leaves. 

 Different branches of Linosyris viscidiflora gave 66, 70, and 80 per cent, of 

 leaves and twigs, and a specimen of L. graveolens 55 per cent. Purshia triden- 

 tata in two trials gave 61 per cent., and Prunus demissa 55 and 68 per cent. 

 In all these cases the leaves and twigs were still green and fresh, though in 

 the fourth week of July. In September and October the weight of the 

 leaves and fruit of Obione confertifolia was 82 per cent, of that of the entire 

 branch. 



It is hence evident that there is no deficiency in the extent of leaf sur- 

 face exposed to the action of the atmosphere, nor in any instance does there 

 seem to have been any unusual want of succulence, the moisture lost amount- 

 ing sometimes to nearly or quite 50 per cent, of the whole substance. 



