iSpz.J Recent Literature. I7Q 



scale between Colaftes auratiis and C. cafer.^' This conclusion seems 

 inevitable, for, while the transition between geographic races is apt to be 

 gradual and symmetrical, what we have here is quite the reverse, an ut- 

 terly irregular intergradation with, at the same time, all sorts of asymmet- 

 rical combinations of the characters of the two birds. 



Mr. Allen has investigated also the geographical, individual and sea- 

 sonal variation among the Flickers, with interesting results. Geograph- 

 ical variation in size amounts in C. auratua to about lo per cent in the 

 length of wing between Arctic America and southern Florida, while the 

 West Indian forms are even smaller. The difference between C. c. satu- 

 ratior and C. rufipilens is nearly parallel to this, but in C. cafer itself the 

 variation is less uniform with latitude, being perhaps complicated, Mr. 

 Allen suggests, by opposing effects of altitude. C. c/rrysoides shows 

 hardly any difference in size geographically. In the Florida auratits, 

 though it is smaller and darker than the northern bird, the average differ- 

 ence "proves too slight and too inconstant, in either size or color, to 

 make a separation practicable." 



Individual variation is considerable, both in size and in color. The bill 

 varies in length from 15 to 25 per cent, the wing from 8 to 12, the tail 

 from 12 to iS In color the variation "affects (i) the size and shape of 

 the circular black spots on the lower plumage, (2) the width and number 

 of the dusky crossbars of the upper plumage, (3) the size and form of the 

 malar stripe, (4) the presence or absence of black spots on the white 

 rump, (5) the tone of color suffusing the general plumage." These vari- 

 ations are discussed in detail, as is the tendency in the females to develop 

 a malar stripe. 



The only seasonal changes in color are those due to fading and abra- 

 sion. 



Throughout the group the nestling plumage differs from the adult 

 chiefly in showing more or less red in the crown and in having the mark- 

 ings in general coarser and heavier. An interesting variation is shown 

 in the malar stripe which in the adults is so prominent, and yet so un- 

 stable, a character. Young C. anrntiis shows in both sexes the black 

 malar stripe that in the adult is confined to the male. In C. ckrvsoides. 

 C. cnfer, and C. c. saturatior this marking is red in the male, and rufous 

 in the female, as in the adults. — C. F. B. 



Chapman on the Origin of the Avifauna of the Bahamas.* — Mr. Chap- 

 man gives a general review of the bird life of the Bahamas, grouping the 

 species, in accordance with their distribution, primarily into two classes : 

 (i) those of more or lessgeneral distribution, numbering 32 species, and 

 (2") species peculiar to the Bahamas, 24 in number. The species of the 

 first class are further divided, as regards their distribution, into cos- 



*The Origin of the Avifauna of the Bahamas. By Frank M. Chapman. American 

 Naturalist, June, 1891, pp. 528-539. 



