interesting and valuable facts respecting it. As will be noticed by the careful reader, he speaks of what he has himself observed, and much of what he says will be new to all but experts, as it has only recently been recognized by science. His observations establish the fact that most of the decay of wood, including what was formerly called eremacausis or slow combustion and dry rot—the name now representing the result, whereas it was formerly held to describe the cause—is produced by the growth of mycelia of fungi, which effect the disorganization of the wood-cells. The figure on page 438, which is from a photograph, tells more on this subject than many pages of letter-press could do. Some of the fungi described and figured by Mr. Dudley are old acquaintances to frequenters of the woods who have observed the curious forms of their pilei on stumps and logs, and have supposed them to be fruits of rottenness. Mr. Dudley exhibits the more essential parts of these fungi, the mycelia penetrating and interpenetrating every part of the interior of the wood, and generating the rottenness of which the pilei are the sign. Some suggestive observations may also be found in the article concerning the relations of moisture to the growth of fungi. Mr. Dudley will continue the subject in another article, with some practical suggestions founded on the results of his investigations.
We print in this number of the "Monthly" the last of the series of papers by Mr. David A. Wells upon the economic condition of Mexico. Accurate information of a country with which we must inevitably come into intimate political and financial relations is in the highest degree desirable, but has heretofore been very difficult to obtain. Mr. Wells—whose competency to perform the task he has undertaken will be questioned by no one—has done a valuable service, making us acquainted with the actual condition of this but little-known country. As he says, the pictures usually drawn of the natural resources of the country and its future possibilities have been rose-colored in the extreme. He finds, on the contrary, that the country is almost hopelessly poverty-stricken—to such an extent, indeed, that the problem of a stable government is beset with the greatest difficulties. With an army consuming a third of the revenue of the state, a system of internal tariffs between each of the States, or political divisions composing the republic, and with an almost entire absence, until very recently, of means of communication between different parts of the country, anything like industrial progress or political stability has been out of the question. His study of the country does not lead him to any very hopeful prediction of its future. Its natural conformation—that of a great table-land, devoid of navigable streams, with a strip of coast-land on either side which can only be reached by abrupt descents—is unfavorable to the material development of the country; while the character of the people, their extreme poverty, and the enormous load of public debt, are almost insurmountable obstacles to any great degree of prosperity. In our own interest, as well as that of Mexico, he bespeaks a kindly and helpful attitude on the part of this country toward the weaker republic, and his words are well worthy the attention of all Americans who desire to see their country without reproach in all its international relations.
Teacher's Hand-Book of Psychology. By James Sully, M. A. New York: D. Appleton & Co. 1886. Pp. 414. Price, $1.50.
In the present work Mr. Sully has attempted to reduce and simplify the statement of scientific principles contained in his former and larger work, "The Outlines of Psychology," and to expand their prac-
