In this way he could have secured for himself the priceless gem of "priority of discovery" without the tedious years of work; he could then have produced what so many scientists in prominent positions produce on subjects fit to occupy one mind for years, a few pages of general discussion and desultory reference to scattered and long-known facts.

The characteristic of exhaustiveness and its consequences is well illustrated in his "detail work" in the Monograph of Cirripedia. By the examination of an enormous number of specimens he showed how very variable are the species of the genus Balanus, and how, through imperfect examinations and want of caution, so many nominal species of fossil Balani have been described. Discussing dubious species, he said, "Bronn does not seem to have been aware of the absolute necessity of giving minute details in his descriptions of fossil cirripeds." Probably in no department of the biological sciences has there been more superficial and worthless work done than in the description of species. This is doubtless. due to the fact that a spurious fame could be acquired by the connection between the author's name and that of the species he described.

1

1 Monograph of the Cirripedia, Vol. II. pp. 173, 184.

Even good naturalists have frequently regarded a short description sufficient for ordinary purposes of identification as even preferable to a minute enumeration of details. Darwin not only gave an example of the permanent worth of the latter method of specific description in his "Monograph of the Cirripedia," but his book on the "Origin of Species" is one of the finest examples extant of the fact that a short statement of any subject to be valuable and forcible must be an abridgment of and be based upon a vast mass of details. In a correspondence with Hugh Strickland he expresses himself almost savagely in condemnation of the wretchedly poor work of species describers; he had unusually good reason to feel aggrieved because the nature of his work compelled him to use so much of the work of others. But he did far less for the improvement of specific description by personal example in the Monograph of Cirripedia, and by personal condemnation of the poor work of others, than he did indirectly by his general theories of descent and natural selection. The doctrine that species had their origin in varieties and in individual variations has changed the purpose of specific description. Identification and classification have been made processes subsidiary to some

thing higher. The establishment of a new standard of value for specific work has not only directed this work into new channels and the careful study of details, but has made many old descriptions valueless.

Intimately connected with the thoroughness with which scientific work is done is the length of time spent on it. One of the serious objections to waiting for better facilities, more evidence, etc., when the question of closing up an investigation arises, is the probability of loss of interest in the subject. Promptness in completing any line of work seems commendable on account of the economy of time, the greater certainty of recording results to date, and the importance of keeping the coast clear for new work. But work "completed" in a short time suffers from incompleteness, from whatever point of view it is regarded. Nothing can be so demonstrative as the relative permanence of work that has been done slowly and work that has been done with promptness and apparent vigor. The latter almost invariably takes a very subordinate place in the literature of the subject when once that subject is competely worked out.

In these days of competition, when every field of biology is ferreted for new subjects of

investigation, and others are likely to secure priority of publication, there is every temptation to publish prematurely. Priority having been gained by a so called preliminary notice, a large proportion of the subjects are dropped by the original investigators, and let alone by others because they are "old." Time makes investigation easier. Where speed is felt to be necessary, a vast outlay of energy is frequently required to discover what with more time would almost come of itself. With the attention steadily fixed, time brings to bear multitudes of facts that would otherwise be lost. Gaps in the evidence, if filled at all, are too often filled with "necessary inferences" instead of facts.

There is perhaps no better case on record to illustrate the effect of time on the development of theory than the “Origin of Species." Darwin had already long reflected on the subject when he opened his first note-book for facts in 1837; and for more than twenty years thereafter he labored in analyzing and interpreting the facts of nature by the help of his theory in order to test the latter in all its relations. By carrying on simultaneously several investigations bearing on the general subject, he could let each of his studies drag through many years, and yet was able to accomplish

much. Some of the most important explanations under his theories did not occur to him until years after he had begun their study. It will be pointed out later that after he once got possession of a working hypothesis his work was largely deductive; and it will be shown how extremely difficult it is to work out all the important consequences of such a hypothesis even in many years. After it is once done the task seems so easy that the wonder is that it was not done sooner. But the contemplation of the development of a great theory soon reveals the enormous difficulties in the way of one or many who seek to work out its consequences. Darwin did in each of his investigations what is usually done for a subject by a number of successive workers; each makes an important contribution to the subject, removes a serious objection to a theory, explains a section of the evidence, points out an important consequence, or modifies the statement of it to bring it more clearly in harmony with the greater knowledge on the subject. By successive approximations many men, working toward the same end, originate, build up, and improve a theory until it takes its place among permanently established truths. As far as it was possible for one man to do so Darwin did all