262 ^he Philippine JowTial of Science 1917 



exhibits a background picture distinct in one or more particulars from 

 every other species, it is possible to identify many of them by the use of 

 the ophthalmoscope alone; * * *. [p. 114.] 



Colored plates show that there is much difference in the 

 fundus of different genera, but in only one case has the author 

 illustrated the fundi of two species in the same genus, namely, 

 Haliaetits leucocephalus and H. leucogaster, illustrated on plates 

 33 and 34, respectively. The ocular fundi of these two species 

 seem to be somewhat similar to each other, but that of the 

 latter seems to be more similar to the fundus of Tinnunculus 

 alaudariiis, plate 35, than to the fundus of H. leucocephalus. 

 Doctor Wood says (p. 115) : 



The arrangement of the centres of distinct vision, the fundus tints and 

 the pectinate tissues of the larger Acciptriformes present a decided oph- 

 thalmoscopic resemblance in all the species so far examined by the writer. 



A series of plates illustrating the fundi of half a dozen or 

 more species in one genus would be interesting. With regard 

 to characteristic colors of the fundus, Doctor Wood says (p. 114) : 



When a bird and his ancestors (in the evolutionary sense) have used 

 their eyes for distinct visualization largely or exclusively at night the 

 fundus tint is nearly always yellow or orange. 



Another observation of avian fundi seems to show that an admixture of 

 yellow (in the form of an orange-red coloration) may be present to in- 

 dicate not so much recent as former, i. e. atavistic, night habits long since 

 abandoned by the species. 



This almost universal occurrence of yellow or orange-tinted fundi in 

 Night Birds leads one to speculate as to the cause of a different colora- 

 tion in species that, during historic times at least, have used their eyes 

 largely or exclusively after dark. At least some of the Ardeiformes furnish 

 such examples. 



The paper, type, press work, and binding of this book are 

 such as to produce a pleasing and satisfactory volume. 



R. C. McG. 



Heridity in Relation | to Eugenics | by | Charles Benedict Davenport | [5 

 lines] I [ornament] | New York | Henry Holt and Company | 1913 | 

 Cloth, pp. i-xi+ 1-298. 



Heredity in Relation to Eugenics is a most welcome contri- 

 bution to the literature of the subject, not only because of the 

 many facts presented, but also because of the clear, sound, and 

 temperate analysis which the author has made of them. What 

 is given here is no more than a brief abstract of this book, and 

 it should be said that the work is an excellent one for those who 

 are interested in the subject, as it covers the field in an adequate 

 manner and avoids those severely technical discussions that 



