552 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
vanced, or positively stated as being beyond dispute. Ail facts bearing 
upon the question, therefore, should be scrupulousiy and methodically 
collected in order to be used as a basis for the formation of rules for the 
guidance of all engaged in cork culture. 
The cork tree (Quercus suber, of Limnzeus) is of various sizes, and this 
has given rise to wide differences of opinion with respect to the greatest 
height and circumference or diameter it attains. According to Mr. 
H. Laure some have grown to the height of fifty feet, and he has seen 
trees of three feet in diameter in the neighborhood of Bormes. Mr. F. 
Jaubert de Passa fixes the maximum height at sixty feet with a diame- 
ter of four feet. In Algeria cork trees sixty-five feet high and from ten 
and a half to sixteen and a half feet in circumference have been found. 
In Estremadura there are some trees as large as those found in Al- 
geria. There is a tradition that in the vailey cf Batuecas (Salamanca) 
there was a large cork tree, the hollow trunk of which was used as a 
cell by some of the monks of a neighboring monastery. In 1862, in a 
cork plantation called Monte Mayor, in the province of Castellon de la 
Plana, cork was taken from a tree 50 feet high by 10 feet in cireumfer- 
ence. ‘This tree was 60 yearsold. Inthe province of Gerona the author 
has seen trees of a greater diameter than any mentioned above, except- 
ing that of the valley of Batuecas, the size of which is not known. 
The tree attains a great age, and its growth continues from one hun- 
dred and fifty to two hundred years. It lives after it ceases to grow, 
but the yield of cork is diminished. 
CONDITIONS UNDER WHICH FOUND. 
Geographical climate—Extensive plantations of cork trees are found 
throughout the greater portion of the countries lying along the Mediter- 
ranean, as far north as the forty-fifth degree of latitude; beyond that 
line they do not flourish, and are sparse and of little value. Its polar 
hne coincides with the isotherm +13.5°, 
Physical climate—Cork tree requires a warm, or at least a temperate 
climate. It is found in Spain, at an altitude of 1,600 feet; at the same 
height in France, according to some authorities, and at 2,600 feet accord- 
ing to others. In Algeria, it grows at an elevation of 3,200 feet. The 
minimum average annual temperature which it can stand appears to be 
+13°.* <A southern exposure is the most favorable to its growth, 
although it does well in other situations when all other conditions are 
propitious. 
The free circulation of air and an abundance of light are highly 
beneficial to the development of this tree, which prefers, therefore, slopes 
to plains, particularly if they are near the sea or immediately on the 
coast. 
According to Antonin Bouset, the cork tree can resist differences of 
temperature of fifty degrees. 
Soil.—Granitic lands and sandy siliceous soils are very favorable to 
the rapid growth of the cork tree, which seems almost to absolutely 
reject those which are purely calcareous. It grows spontaneously in 
virgin soils, where silica or silico-argillaceous compounds are abundant. 
It does not affect damp lands, and shuns marshes. In proof of this 
it will only be necessary to examine the lands occupied by the cork 
plantations in the provinces of Caceres, Gerona, Castellon, and other 
*The author does not say whether this temperature is according to the Reaumer 
or the Centigrade system. If the Reaumer is meant, it is equal to 61.25° Fahrenheit; 
if the Centigrade, to 55.2° Fahrenheit. It is almost safe to assume that the Centigrade 
is meant. 
