56 THE AMERICAN NATURALIST [Vol. XLV 



peculiarities that have not appeared in any previous ac- 

 count, seems to be worthy of record. It should be kept 

 in mind, however, that the value of such descriptions does 

 not come from the morphological features revealed, no 

 matter how bizarre these may be, but from the fact that 

 considerable light is often thereby shed on the complex 

 physiology of the reproductive organs, and it is with 

 this idea in mind that the following record is made. 



The egg in question, which was kindly handed to me 

 by Mr. S. L. Pinckney, Austin, Texas, was laid March 28, 

 1910. It was stated that several double eggs had been 

 received from the flock from which this egg came, but 

 whether they were all laid by the same hen could not be 

 ascertained. The egg was large, measuring 85 mm. in 

 its long axis and 62 mm. in the short axis, and was 

 slightly smaller at one end than at the other, so that we 

 may speak of the blunt and pointed ends. It was prac- 

 tically a soft-shelled egg, in that the amount of lime de- 

 posited on the shell-membrane was very small, and for 

 the most part was collected into little nodules scattered 

 about over the surface (Figs. 1 and 2). A microscopical 

 examination of the shell 11101111)171110 did not reveal any- 

 thing unusual, for it consisted of the two characteristic 

 layers, a thick outer and a thinner inner; but on cutting 

 it open I was surprised to find another shell-membrane 

 lying almost directly beneath it (Fig. 2). The two mem- 

 branes were separated by the very thinnest layer of 

 watery albumen. This second or inner membrane was in 

 every way normal, and perfectly white, but was entirely 

 void of lime deposits, reminding one very much in its gen- 

 eral appearance of the membranes on eggs which have 

 just reached the isthmus. 



The contents of the inner shell-membrane consisted of 

 much albumen in which were imbedded a hard-shelled 

 egg and a yolk (Fig. 3). Upon examination the inclosed 

 egg was found to be perfectly normal in every respect, 

 and its yolk contained a healthy blastoderm. The in- 

 closed yolk, although normal in structure, was much dis- 



