98 THE CONDOR Vol,. X

ined after it has taken place, a slight darken- ing of the new feathers is noticeable. "A rad- ical change in the pigmentation of the plumage takes place with each succeeding molt." The darkening seems to parallel the coloration of the wild species; that is, after the first molt the bird is similar to the wild Scardafella inca dia- leucos, .which inhabits Honduras and Nicara- gua. Lat&r molts bring the subject in line with Scardafella ridgvayi of Venezuela and Brazil. Finally it became so dark that there is rio wild species with which it may be com- pared. In the birds experimented on a steady increase of melanin, both in the feathers and in the choroid coat of the eye, takes place until finally no white feather areas at all are left. Many wild genera of tropical doves are char- acterized by an iridescence of the wing coverts and inner secondaries. A remarkable feature of the color change of Mr. Beebe's subjects is the appearance of iridescence upon these feath- ers as a certain stage of melanin concentration is reached. In discussing the results of his experiments, the author considers the following subjects, Significance in Respect to Direction of Evolu- tion, Correlation with Natural Selection, Cor- relation with Taxonomy, and Correlation with Organic Selection. The doves or Columbiformes are for the most part tropical in distribution, and it is probable that those which range farther to the north are tropical in origin. Since in these experiments the color characters assumed are progressively parallel to species farther toward the fropies, we apparently have an instance of "reversal of the direction of evolution." As the "recapitu- lation follows the same lines as in related genera of doves", and the details of change are identical in several individuals, Mr. Beebe decides that his work supports the orthogenetic hypothesis. He says that acquired and in- herited characters should be clearly distin- guished. The experiments here recorded show that the Scardafella specific differences are merely ontogenetic, or acquired characters. "Mutation and natural selection have no place in these experiments." Still Mr. Beebe is led to the conclusion that natural selection is important in nature. For example, if the white color of Arctic animals is purely the re- suit of environmental modification of pigment production "why does not the snowy owl change in summer like the ptarmigan", and why do some m.ammals remain dark thruout the year, while others are white at certain seasons? Natural selection probably comes continuously into play, modifying the direct climatal effect in accordance with the needs of each species. The rapid response to environ- ment recorded in these experiments is likely to shake the ideas of "gradual evolution" and "long-continued action of environing condi- tions upon the whole organism." The writer thinks that it would be unreaon- able to discard species whose distinctive char- acters are found to be merely acquired, for often there is a geographical hiatus between the species, and other differences, for instance in habits, would be swamped under one name. "Any correlation of the results outlined in the present paper with the various theories of evolution must be tentative in the present state of our knowledge." This point we think should be emphasized, for when an individual of a wild species is experimented upon in confine- ment the fine adjustments of nature are broken down, and many subtle influences we do not now understand may be taken from it or brought to bear upon it, perhaps wholly ob- scuring the truly significant features. Mr. Beebe asserts that his experiments seemingly support the theory of organic selection; he gives as a possible adaptive character the pres- ence of increased pigment in epidermal struc- tures in a hot moist climate---adaptive in that this pigment absorbs the irritating ultra-violet rays of light. Compared with animals of the arid deserts, however, animals in the hot, moist, and therefore cloudy climates receive comparatively little light, and we should ex- pect the former would exhibit the most abun- dant epidermal pigment supply! The follow- ing-proposition seems justifiable, however, "if a new character, ontogenetically acquired, is in any way adaptive, it might easily be the means of preserving the species until phylo- genetic variation had impressed it upon the race. ' ' The paper constitutes one more step toward the placing of experihental biology upon a basis of importance in research work on the great problems of the science. The impres- sion left on the eviewer, however, is that of the exploitation of the unknown rather than addition to the known.--l'aller .. Taylor. MINUTES OF COOPER CLUB MEETINGS NORrHERN mvrsroN JxNJXR.--The regular annual meeting for the election of officers of the Northern Division of the Cooper Club was held at the Chamber of Commerce, corner of Twelfth and Franklin Streets, Oakland, Saturday evening, January 11, 1908. Preceding the business session Mr. Edw. W. Gifford, assistant Curator of Ornithology in the Academy of Sciences, San Francisco, spoke on "The Restoration of the Academy Collec- tion." Mr. Gifford referred to the good for- tune of the Academy in receiving the collec-

tions of the Beck Expedition after the fire, thus