a 
14 ORNITHOLOGY AND OOLOGY. 
becoming larger on the smaller end towards the middle, and the 
red patches on the larger end increase towards the same point, 
where the colors meet and become mixed in irregular patches of 
various sizes, from mere dots to blotches. ‘The smaller end has a 
few streaks and blotches of dark-purple overlying apparently the 
other colors, as in specimen No. 1. 
“These specimens are very interesting, as indicating the great 
amount of variation to which the American Peregrine’s eggs are 
subject; and especially so since they are all the product of one pair 
of birds, laid in one set, and identified as such beyond question. 
In coloration, a transition can be traced between the extreme in the 
order they are numbered, which is undoubtedly the order in which 
they were laid, as indicated by the thickness of the shell as well as 
by the depth of color. 
TABLE OF COMPARATIVE MEASUREMENTS. 
Prop. of breadth Point of greatest transverse 
Length. Breadth. to length. diameter from small end. 
No.1. ... . . - 218in. 1.71in. 0.785 in. 0.640 length of the egg. 
No.2. = beep BO1 gin ABT a, eo as UODAOy) 
Nastte etch Mobs SBR” MeO MOOR) te OObob: re eee 
Wotdes a Cabin SAG at ABBA 40 E5 ES 0 nebo, Ene eee 
Average. » » » « +» 222),, 1.68 ,, 0.759 ,, O609\ rs fin see eee 
Greater extreme . . . 2.82.,,, Thal 5 ON 8b in. 0:66. 5,1 ant ales 
Lesser extreme .. . 2.16 ,, 1.65 ,, O:782. 55). OL04 05) ie cet cama 
Amount of variation . 0.16 ,, 0.06 ,, OF058' 5) OTTO || esse arieeaes 
Dr. Brewer’s specimen . 2.00 ,, 1.56 ,, 0.780 ,, 
“ From the above table, it will be seen that the range of varia- 
tion in the four specimens in length is .16 of an inch, or nearly 
seven and a half per cent of the average length; in breadth, .06 
of an inch, or about three and a half per cent of the average 
breadth: in the proportion of breadth to length, about fifteen per 
cent of the length, or nearly twenty per cent of the average pro- 
portion. The variation in the position of the point of greatest 
transverse diameter is about eleven and a half per cent of the 
whole length of the egg; the form of the eggs varying from an 
ellipsoid in No. 2 to an ovoid, which, in No. 3, has the smaller end 
considerably elongated. It will be observed that the egg meas- 
ured by Dr. Brewer is considerably smaller than my smallest 
specimen, and that the proportion of breadth to length scarcely 
differs from the same proportion in No. 1. 
