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. Later molts bring the subject in line 

 with Scardafella ridgivayi of Venezuela and 

 Brazil. Finally it became so dark that there is 

 no 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 Cohunbifoinnes 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 tropics, 

 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- 

 sult of environmental modification of pigment 

 production "why does not the snowy owl 

 change in sunimer like the ptarmigan", and 

 why do some mammals remain dark thruout 

 the year, while others are white at certain 

 seasons? Natural selection probably conies 

 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 unreason- 

 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 experimental biology upon a 

 basis of importance in research work on the 

 great problems of the science. The impres- 

 sion left on the reviewer, however, is that of 

 the exploitation of the unknown rather than 

 addition to the known. — Walter P. Taylor. 



MINUTES OF COOPER CLUB MEETINGS 



NORTHERN DIVISION 



January. — 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." j\Ir. Gifford referred to the good for- 

 tune of the Academy in receiving the collec- 

 tions of the Beck Expedition after the fire, thus 



