Vol i 9 ^ in ] Recent Literature. 113 



best as only casual, and the infertility of hybrids, especially among the 

 higher animals, is too well known to need further comment here"! He 

 believes that in the case of these two forms, "we have examples of two 

 separate and distinct 'mutations' from a common parent stock or species. 

 That is," he continues, "I believe that H. pinus, early in the last century 

 became unstable as a species and began to throw what must be considered 

 as 'mutants,' taking de Vries's definition of the word." He concludes 

 with the following: " In the light of the evidence set forth only one answer 

 can be made to the question as to the part that the process defined by 

 de Vries as mutation is playing among higher animals to-day. Beyond 

 doubt we have witnessed the birth of new species of birds during the past 

 seventy years. Moreover, some of these new species have flourished so 

 as to have become a salient part of the bird fauna in the region where they 

 occur and where they were unknown to skilled ornithologists, who care- 

 fully studied these regions in the early part of the last century." Else- 

 where in his paper he lays great stress on the fact that these forms were 

 unknown to "such keen field naturalists as Audubon and Wilson, [Nuttall,] 

 Lawrence, Coues and Prentiss." 



Having elsewhere replied l in considerable detail to Mr. Scott's paper, 

 we will here merely state, (1) that the area where these birds have been 

 found (except in the case of a very few migrants) was wholly outside of 

 the regions studied by the above named "keen field naturalists," and 

 that their ignorance of these birds does not imply their absence from the 

 area where they have since been found in some numbers, and their probable 

 recent origin; (2) that these birds do not present the stable character 

 observed in mutants, which always breed true; (3) that they occur only 

 where the breeding ranges of Helminthophila chrysoptera and H. pinus 

 overlap, and are thus strictly comparable with the hybridity seen on a 

 grand scale between Colaptes cafer and C. auratus over the extensive region 

 where their breeding ranges overlap; (4) that Mr. Scott has not shown a 

 very clear grasp of the facts in the case of these warblers, or of the real 

 character of mutants; (5) that the hypothesis of hybridity, plus more or 

 less tendency to dichromatism, satisfactorily accounts for H. lawrencei 

 and H . leucobronchialis and their endless variants. — J. A. A. 



Clark's ' Birds of the Southern Lesser Antilles.' — This paper, of over 

 one hundred pages, 2 relates to Barbados, St. Vincent, the Grenadines, and 

 Grenada. Twenty-five pages of introductory matter treat of the ' Litera- 

 ture,' 'Geology and Geography' (pp. 206-215), 'Meteorological and Geolo- 

 gical Phenomena' (hurricanes and volcanic eruptions), 'Present Status of 

 Bird Life,' 'Locally Extinct Species,' 'Introduced Species,' 'Exported 



Science, N. S., Vol. XXII, No. 562, pp. 431-434, Oct. 6, 1905. 

 ■ 2 Birds of the Southern Lesser Antilles. By Austin.H. Clark. Proc. Boston Soc. 

 Nat. Hist., Vol. XXXII, No. 7, pp. 203-312. Oct., 1905. 



