An Ecologist's Garden. 65 
rounded outlines. The Herault has cut itself a rugged gorge with 
almost precipitous sides. The difference is, of course, due to the 
much greater proximity of the Mediterranean, and no more striking 
illustration of this phenomenon of erosion could be found. 
Geologically the Aigoual is composed of mica schists with 
frequent limestone bands. These are generally extremely firm, 
occur as lamellae in the schist, and are recognised by the type of 
weathering. But here and there bands of very considerable thickness 
occur—their position is frequently indicated by a disused limekiln— 
and these bands of precambrian limestone are one of the most 
interesting features of the mountain. Fifty years ago the Aigoual 
was entirely deforested: it was even possible to refer to its shining 
top as an example of the physical properties of mica-schist. Now, 
however, it is in active process of afforestation and is for the most 
part covered with plantations of larch, pine and fir. 
The suitability of the situation for the establishment of an 
ecological garden is manifest when we note:—(i.) the geographical 
position between Atlantic and Mediterranean basins; (ii.) the 
elevation, which permits of a flora of the mid-European mesophytic 
type within fifteen miles of the markedly xerophytic Mediterranean 
flora; (iii.) the geological composition, which offers both calcareous 
and siliceous soils (it may be noted that granite occurs in the 
immediate vicinity) ; (iv.) the afforestation. 
The idea of an experimental garden originated with M. Georges 
Fabres, the forestry inspector for the department, a man whose 
best monument is the reforested Aigoual. Thirty years ago he 
started making collections of various foreign trees round several of 
the stations. In 1903 the Director-General suggested to him and 
to Professor Flahault that a regular botanical garden might be laid 
out. Three sites were chosen. On the summit of the Aigoual it 
was found impossible to obtain satisfactory results owing mainly to 
the unceasing winds which swept it. A bog forming the source of 
one of the Atlantic streams has been utilised for experiments with 
such trees and shrubs as are willing to grow in very damp stations. 
The third and most important —the garden proper—occupies 
about two acres of ground on the southern side of the mountains, 
It lies about 800 feet below the summit, at a point where the slope 
is less rapid than immediately above and below. It is, in fact, like 
the seat of an arm-chair, the back of which is formed by the 
mountain side below the neck, which joins the Aigoual to the Pic de 
la Fajolle. Two ridges close it in like arms. In front the seat 
narrows and ends in the precipitous valley of one of the tribu- 
