Linnæus' contributions to zoology consisted mainly of the introduction of his most ingenious and helpful system of bookkeeping. By it naturalists of all lands were able to speak of the same species by the same name in whatever tongue. Unfortunately, ignorance, carelessness, and perversity brought about a condition of confusion. For a long period many species were confounded under one name. This source of confusion began with Linnæus himself. On the other hand, even with Linnæus, the same species often appeared under several different names; in this matter it was not the system of naming which was at fault. It was the lack of accurate knowledge, and sometimes the lack of just and conscientious dealing with the work of other men. No system of naming can go beyond the knowledge on which it rests. Ignorance of fact produces confusion in naming. The earlier naturalists had no conception of the laws of geographical distribution. The "Indies," East or West, were alike to them, and "America" or "India" or "Africa" was a sufficiently exact record of the origin of any specimen. Moreover, no thought of the geological past of groups and species had yet arisen, and without the conception of common origin, the facts of homology had no significance. All classification was simply a matter of arbitrary pigeon-holing the records of forms, rather than an expression of actual blood relationship. To this confusion much was added through love of novelty. Different authors changed names to suit their personal tastes regardless of rights of priority. _Amia_ was altered to _Amiatus_ by Rafinesque in 1815 because it was too short a name. _Hiodon_ was changed to _Amphiodon_ because it sounded too much like _Diodon_, _Batrachoides_ to _Batrictius_ because ~batrachos~ means a frog, not a fish, and other changes even more wanton were introduced, to be condemned and discarded by the more methodical workers of a later period. With all its abuses, however, the binomial nomenclature made possible systematic zoology and botany, and with the "Systema Naturæ" arose a new era in the science of living organisms. In common with most naturalists of his day, the spirit of Linnæus was essentially a devout one. Admiration for the wonderful works of God was breathed on almost every page. "O Jehovah! quam ampla sunt opera Tua" is on the title-page of the "Systema Naturæ," and the inscription over the door of his home at Hammarby was to Linnæus the wisdom of his life. This inscription read: "Innocue vivito: Numen adest" (Live blameless: God is here).