230 Shufeldt, Eggs of Reptiles and Birds Compared. [isfwii 



equally shown by the clearly-defined hau--lines or vermiculations 

 seen in many eggs, and in none more commonly met with than 

 in those of most Buntings {Emherizida). Such markings must 

 not only have been deposited while the egg was at rest, but it 

 must have remained motionless until the pigment was completely 

 set, or blurred instead of sharp edges would have been the result " 

 (Art. Eggs, p. 186). 



If an e^g be "at rest " in the oviduct during the course of its 

 descent, and at a point where the pigmentary glands open into 

 that passage, I can understand that, when they discharge their 

 pigment on to the shell of the egg — the latter being stationary — 

 spots and blotches of various sizes, with sharp edges, would be 

 produced ; but just how such a gland could produce the fine, 

 scraggly, hair-like markings in such eggs as are here shown in 

 figs. 32-36 and fig. 38 it is not easy to imagine. To make such 

 markings as those, the egg must have been stationary, while the 

 wall of the oviduct, containing the pigment glands, must have 

 moved and contracted in various ways and directions while the 

 pigment was being delivered, in very small quantities, but in full 

 strength. In other words, were we to attempt to make such 

 markings on the shell with a pen (a fountain pen, for example, 

 charged with pigment), it must be clear that, in order to depict 

 such line-markings, the egg must either rotate to and fro about 

 its longitudinal or other axes, the pen-point being held in contact 

 with the shell, or else the egg must be fixed and stationary while 

 the hand holding the pen does the work by tracing on the shell 

 the various irregular lines and markings as we see them in the 

 figures on the plate. In other words, it would seem that the 

 contraction of the o\dduct during the passage of an egg, par- 

 ticularly when the latter passes the part of the canal where the 

 pigmentary glands are in operation, is both peristaltic and anti- 

 peristaltic, with an action sometimes combining both of these 

 movements. It is difficult for me to see how the tracings laid on 

 the shell of the egg of the Regent Bower-Bird {Sericulus melinns) 

 could have been accomplished in any other way. 



In such eggs as the Lesser White-backed Magpie [Gyntnorhina 

 hypoleuca) sometimes lays (see Plate XL., fig. 37), which have a 

 ground colour of a rather light olive-green, and where the pale, 

 rusty, hair-line markings are extremely fine, dense, and equally 

 distributed over the entire shell, the deposition of these latter is 

 more difficult of explanation. The markings in question exhibit 

 some blurring, which is decidedly the case with the faint, diffuse, 

 and not large blotches, of various sizes, scattered over the surface 

 of the shell, with no special congregation at the apex or butt. 



There is but one way known to me through which an exact 

 explanation of how markings of this character were deposited upon 

 the shell can be obtained : by securing a sufficient number of 

 recently-shot females, in which the eggs were in the course of 

 passing through the ovdducts. In such specimens, careful gross 

 and microscopical examination of all the ' structures concerned — 



