^"'igi^)^'] Shufeldt, Es:^s of Reptiles and Birds Compared. 220 



graphing them I simply turned each egg comi)lcteIy over in order 

 to get the appearance of the other side.) These eggs are not 

 glossy, being of an extremely pale cream colour ; the markings are 

 a very dark, rich, Vandyke brown, interspersed with a few blotches 

 and smaller spots and specks of pale grey. The former are chiefly 

 near the butt, while the big brown blotches are situated, in two 

 instances, toward the big end (figs. 29, 31), and ]:)ctwcen tlic two 

 extremities in another (fig. 30). 



This pigmentation shows no smearing whatever, and in nvuncrous 

 instances the brown spots and blotches overlie the grey ones, 

 indicating that, as the egg rested at two different points in its 

 descent down the oviduct, the brown markings were the last to 

 be deposited upon its shell ; this, however, will not account for 

 the unusually big blotches of brown being only upon one side of 

 the egg. And while two of these eggs may have descended the 

 oviduct butt first — the heavy pigmentation being at that end — 

 it is not at all clear that the one shown in fig. 30 did, for there the 

 great, square, unsmeared spot is directly on the side of the shell. 



Again, where the markings are as heavy as these, the egg must 

 have made quite a pause in its descent, at some point opposite 

 the pigment glands, in order to have these heavy markings set ; 

 or else that peculiar pigment of the seven varieties known may 

 possess the property of setting with great rapidity. Some eggs 

 of other species of birds, however, exhibiting markings of many 

 shades ancl tints of brown, often have the edges of those markings 

 smudged or blurred, which is good evidence that the egg started 

 again down the oviduct before the colouring matter had an oppor- 

 tunity to set. 



Long ago Sorby analyzed these pigments by means of the spectro- 

 scope, and he named seven or eight of them ; but whether any 

 further discoveries have been made of late in that direction, I am 

 not, at this moment, able to say. (P.Z.S., 1875, pp. 351-365.) 



After Mr. Bartlett's actual experiments at the Zoological Gardens 

 of London, a number of years ago, no doubt seems to be left in 

 the minds of naturalists but that the big end of a bird's egg — when 

 that egg was of an ovate form — faced posteriorly in the descent 

 down the oviduct. That there are numerous exceptions to this 

 rule, however, there is no manner of doubt. It is best proven 

 by the eggs in certain small Falconidce, where a band of spots or 

 other markings surrounds the egg not far from the apical end of 

 it — sometimes even overlying that point. 



The markings on the eggs of some of the Icteridce cannot, to my 

 mind, be explained so easily ; and it is still more diiiticult of 

 explanation in such an egg as is laid by the Regent Bower-Bird 

 {Sericiiliis melinus) of Australia (fig. ^^, Plate XL., which compare 

 with figs. 32, 34, 36, and 2fi of the same plate). Newton, in his 

 " Dictionary of Birds," says : — " Li addition to what has been 

 said above as to the deposition of colour in circular spots indicating 

 a pause in the progress of the egg through one part of the oviduct, 

 it may be observed that the cessation of motion at that time is 



