All fossils follow the same developmental law, and seem to have been governed by corresponding conditions everywhere. The doctrine of "_similia similibus gignuntur_"--similar conditions producing similar forms--obtains universally. The _Graptolites_, occurring in the bituminous shales of the Silurian sandstone period, afford only another instance of the same law to which we have called the attention of our readers. In fact, the annals of natural history abound in the most conclusive proofs, as well in the fossilized as the living world, of what the paramount text of the Bible teaches us. When Professor Ehrenberg, one of the most distinguished classifiers of minute forms of life in the world, declared, as he recently did before the Royal Geographical Society of London, that there was "a great invisible rock-and earth-forming life in nature," he came pretty near enunciating a great truth in science; and had he connected his language with the induction of "environing conditions" and the sequence of life therefrom, he would have accomplished what we undertook to do in our work begun several years ago, but not completed and published until 1880. For it will be seen that we had been gathering the material for "Life: Its True Genesis" for many years before we sat down to the task of writing it. When we said to one of our most intimate college friends that we were less than six months preparing it for the press, we stated what was literally true; but we had no intention of giving him to understand that we had spent only that time in gathering the vast amount of material at our command--twenty times as much as we could possibly use in the preparation of such a volume for the press. The long months and even years of toil and study spent by us in the needful preparation, were a part of the labor, as every author, writing intelligently on any subject, knows. The immense amount of care and labor that enabled Hermann von Meyer to prepare his paper on the _Archæopterix_, rescued from the lithographic slate, is a case in point, as showing how small apparently the labor of accomplishing a great work for science. The time devoted to preparing the paper was trifling as compared with the result of his achievement. And so with every one who enters the temple of science with a devout wish to attain success. It will be apparent to the religious mind of this country and England, if not to that of Mr. Tyndall himself, that, if the exegetical rendering we have extended to the Bible be correct, there is no necessity whatever for the vast uncomputed periods of time intervening the different geological strata, to which that scientific gentleman refers in his fanciful musings upon the Matterhorn!