882 EXCLUSION OF QUADRUPEDS. 
Exclusion of Domestic Quadrupeds. 
But probably the most important of all rules for the govern- 
ment of the forest, whether natural or artificial, is that which 
prescribes the absolute exclusion of all domestic quadrupeds, 
except swine, from every wood which is not destined to be 
cleared. No growth of young trees is possible where horned 
cattle, sheep, or goats, or even horses, are permitted to pasture 
at any season of the year, though they are doubtless most de- 
structive when trees are in leaf.* ‘These animals browse upon 
tions of climate, hardly resists complete decomposition for a generation. The 
forests of Europe exhibit similar facts. Wessely, in a description of the primi- 
tive wood of Neuwald in Lower Austria, says that the windfalls required from 
150 to 200 years for entire decay.—Die Oecsterreichischen Alpenlinder und thre 
Forste, p. 312. 
The comparative immunity of the American native forests from attacks by 
insects is perhaps in some degree due to the fact that the European destruc- 
tive tribes have not yet found their way across the ocean, and that our native 
species are less injurious to living trees. On the European lignivorous insects, 
see SrmMonI, Manuale @ Arte Forestale, 2d edizione, pp. 369-379. 
* Although the economy of the forest has received little attention in the 
United States, no lover of American nature can have failed to observe a 
marked difference between a native wood from which cattle are excluded 
and one where they are permitted to browse. A few seasons suffice for the 
total extirpation of the ‘‘ underbrush,” including the young trees on which 
alone the reproduction of the forest depends, and all the branches of those 
of larger growth which hang within reach of the cattle are stripped of their 
buds and leaves, and scon wither and fall off. These effects are observable 
at a great distance, and a wood-pasture is recognized, almost as far as it can be 
seen, by the regularity with which its lower foliage terminates at what Rus- 
kin somewhere calls the ‘‘ cattle-line.” This always runs parallel to the sur- 
face of the ground, and is determined by the height to which domestic 
quadrupeds can reach to feed upon the leaves. In describing a visit to the 
grand-dueal farm of San Rossore near Pisa, where a large herd of camels is 
kept, Chateauvieux says: ‘‘In passing through a wood of evergreen oaks, I 
observed that all the twigs and foliage of the trees were chpped up to the 
height of about twelve feet above the ground, without leaving a single spray 
below that level. I was informed that the browsing of the camels had 
trimmed the trees as high as they could reach."_—LULLIN DE CHATEAU- 
vinux, Lettres sur UV Italie, p. 118. 
Browsing animals, and most of all the goat, are considered by foresters 
