The portions of the Catacombs that were excavated during the fourth century vary considerably in character. In some parts, everything is on an exceptional scale of grandeur; the chambers are not only double, one on either side of the gallery, but even treble and quadruple, and of magnificent proportions. In other parts, on the contrary, there is nothing but a number of miserable galleries, executed with great economy, and destitute of all ornament; evidently they were required to meet the increasing wants of a large Christian population. It is during this same period that we meet with inscriptions recording contracts for the purchase of graves, and many more which, without entering into details, merely declare that the deceased had provided during his lifetime a place of burial for himself alone, or for himself and his wife, and perhaps some other relatives also. These have very rarely been found in the more ancient parts of the Catacombs. Indeed, such purchases would have proved a fruitful source of embarrassment in the days of persecution, when the _fossors_ often used galleries whose walls had been already filled with graves as a convenient place in which to deposit the soil removed from the new galleries they were excavating, and sometimes even buried corpses in the pathways which they had thus filled. But this could not have been done if it had been necessary to reserve particular spots as the private property of persons hereafter to be buried there. In the earliest of the inscriptions which record the purchase of graves, the _fossors_ appear as the vendors; indeed, towards the end of the fourth century, it would almost seem as though the whole administration of the Catacombs had fallen into their hands. Each _fossor_ now worked either independently, or with a partner if he preferred it; at least, the purchase is generally stated to have been made from one _fossor_, occasionally from two; and if the names of others of the same class are added, it is only to say that they assisted as witnesses of the contract. Once we even find the family of a _fossor_ selling the graves which their father had excavated. In several of the inscriptions the price is named, as well as the names of the contracting parties; and some authors have attempted to estimate from these examples the ordinary cost of a grave in the Catacombs. Their calculations, however, cannot be accepted, for several reasons. First, the recorded prices are, in every instance, out of all proportion with the labour really expended on the grave; and secondly, they vary immensely, yet not according to any fixed principle. It seems safer, therefore, to conclude, with De Rossi, that the price was in each case proportionate to the means and good-will of the purchaser, that so provision might be made for the gratuitous burial of the poor out of the superabundant payments of the wealthy.