IOWA ACADEMY OF SCIENCES. 



139 



inches long. The fruit spurs are decidedly like those of Malus 

 and thorns do not occur. 



Irregularities in leaf characteristics, vigorous growth, 

 diminution of reproductiveness, all indicative of hybridity, are 

 present, and we give it as our opinion that this crab is the 

 result of a cross of 3falus and lowensis. The seeds average 

 3.1 to the apple. 



Fig. 9. Section of Mercer, showing seeds. Reduced M. 



Size two by two, form oblate, color green, turning to yellow, 

 skin smooth, greasy, cavity broad at mouth, sloping gradually, 

 calyx small, closed, basin abrupt, corrugated, stem slender, 

 one-half inch to five-eighths inch, flesh greenish-white, crisp. 



Fig. 10. Mercer. Foliage, fruit spur and fruit. 



