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and Ar‘zona, including some of the rarest and most interesting trees ot 
that country, particularly the tree Yuccas and a recently-kuown Palm. 
There are fifty species from the Pacific slope of California, and ten or 
twelve from Oregon, and thirty from the Sierra Nevada Mountains of Cali- 
fornia, including large sections of some of the noblest coniferous trees of 
the world, such as the Sugar-Piné, the Douglas Spruce, the Silver Fir, 
and others. From the mountains of Utah and Colorado there are twenty- 
five to thirty species. From Illinois and the Western States, fifty; from 
Vermont, twenty; from Virginia, fifty, most of which were obtained 
from the old Mount Vernon estate of General Washington. The South- 
ern States, exclusive of South Florida, contribute about ninety species. 
The Oak family is represented by thirty species, including the famous 
live-oak of the South, the various white and black oaks, both ofthe 
eastern and western portions of the continent. The Pine family is also 
represented by thirty species, of which more than half are peculiar to 
the Rocky Mountains and western coast. Of Spruces there are sixteen 
species. and of other conifers about twenty. 
GARDENS AND GROUNDS. 
The superintendent of gardens and grounds, William Saunders, who 
is also in charge of the Department collections at the Centennial, ex- 
hibits a plan of the grounds of the Department at Washington, with a 
catalogue chart of the different orders represented in the Arboretum, 
and sundry photographic views of different sections of the grounds, 
MICROSCOPY. 
The exhibit of the microscopist, Thomas Taylor, consists of about five 
hundred water-color drawings, the larger proportion representing the 
leading types of the genera of microscopic fungi; another section of the 
exhibit presents the results of original investigation upon chemical tests 
for flax, cotton, ramie, silk, wool, hair, and both animal and vegetable 
cellulose; and still another series, illustrating the principal vegetable 
starches to the number of about one hundred varieties. . These draw- 
ings present highly magnified views of all these microscopic objects, 
including those most important in economic mycology, especially the 
fungi commonly known as molds, so destructive to vegetation.. The 
edible and poisonous mushrooms are distinguished in one class of these 
drawings. The mycologist proposes to make a collection of all the 
known edible mushrooms of the United States, of which descriptions 
will from time to time appear in the Monthly Report. 
CHEMICAL DIVISION. 
The chemist of the Department, William McMurtrie, presents the 
following description of his exhibits: 
Agricultural chemistry may be defined to be the study of the chemical properties and 
relations of soils and fertilizers, and of those agricultural and horticultural products 
resulting from their manipulation, the value of which depends upon their chemical 
composition and the methods for the utilization of which involve chemical processes. 
This may on some accounts be considered a somewhat comprehensive definition, but it 
embraces only such matters as legitimately fall within its scope, and it covers the 
ground laid out by the chemical division of the Department of Agriculture for the col- 
lection to be shown in the Government exhibit in the International Exhibition of 1876, 
designed to illustrate the objects and ends of the division, viz, the collection and dis- 
semination of information of agricultural interest and of a chemical character, 
