Very little, however, has been added to our knowledge of the life-history of these remarkable architects for several years past, and, indeed, I think it may be safely asserted that the study of the habits and interdependence of the members of the animate world has not, during the last fifty years, made anything like a corresponding progress to that which may be seen in classification and description. The microscope has led many who, a century ago, would have found their chief delight in observing those points in the habits and external characters of living creatures which the naked eye could readily seize upon, to look much closer, to anatomize and describe in detail every organism, great and small, and to examine every tissue and cell. It is, however, to the materials now being amassed by these modern "cabinet naturalists" that recourse must be had if we wish to form a true comprehension of the functions and habits of living things. They must tell us, for example, what instruments, tactile and visual, an animal possesses if we wish to understand how it constructs a particular fabric, so that the "field naturalist" will have to apply to his brother of the "cabinet" before he can turn his observations to good account. Still, the fact remains that the habits of plants and animals afford many openings for careful investigation, and such as are especially within the reach of those lovers of nature who have ample time at their disposal, and the opportunity to spend it in a warm climate where life abounds, and is never wholly checked even in the depth of winter. It seems strange to think that collectors so frequently take creatures out of wonderfully constructed nests and yet never observe, or at any rate never describe, the structure of these fabrics. Thus, for example, the dwellings of only eight out of the thirty-six species of trap-door spider stated by Prof. Ausserer[46] to belong to the Mediterranean region are known in books, those of the remaining twenty-eight being, as far as I have been able to learn, yet to be discovered. This is the more strange as from the nocturnal habits of these creatures it is almost always necessary to dig them out of their nests; indeed it is more than probable that if all the dwellings which have been destroyed had been described, the following pages would never have appeared. [Footnote 46: Prof. Ausserer (Anton.), Beiträge zur Kenntniss der Arachniden Familie der Territelariæ (Mygalidæ), in Verhandlungen der k.k. Zool. Bot. Gesellschaft in Wien. Jahrg. 1871, Band xxi.]