348 MAINE AGRICULTURAL EXPERIMENT STATION. I916. 



ing which appear on the cultivated grain in the second genera- 

 tion. The relation of these to the color and other characters is 

 discussed. 



The heavy pubescence at the base of the grain as well as that 

 on the pedicel is also linked in its inheritance with the wild 

 type of base. The linkage in these cases appears to be absolute 

 since in this cross no wild plants were found which lack the 

 heavy awns and the pubescence described above. 



The pubescence on the back of the two grains is inherited 

 in a peculiar manner. The pubescence on the back of the 

 larger or lower grain of the spikelet is linked with the factor 

 for black color, but the linkage is not absolute, although very 

 close. This linkage is of such a nature that when the cross is 

 made as described above, one out of every 150 F2 plants will 

 be either a black grain without pubescence or a non-black grain 

 with pubescence. 



On the other hand the pubescence on the back of the smaller 

 or upper grain will appear only when the lower grain is also 

 pubescent. Even then it appears very infrequently on grain 

 which has a cultivated base. In other words, the factor for 

 pubescence on the back of the upper grain is linked with the 

 factor for the wild base of the grain. 



STUDIES ON THE PHYSIOLOGY OF REPRODUC- 

 TION IN THE DOMESTIC FOWL. XVI. DOUBLE 

 EGGS.* 



Among the eggs of the domestic fowl an egg which contains 

 another egg is quite rare, but one or more such specimens have 

 been observed by most persons who have handled large num- 

 bers of eggs. This phenomenon has excited the interest of 

 poultrymen and scientists and a number of specimens have 

 been described in the agricultural and scientific literature. The 

 purpose of the paper abstracted is to describe several specimens 

 observed at the Maine Agricultural Experiment Station which 

 have been laid or have been found partly formed within the 



*This is an abstract of a paper by Maynie R. Curtis, having the same 

 title and published in the Biological Bulletin, Vol. xxxi., No. 4, pp. 181-206, 

 jqi6. 



