78 



also been ohsiTvcd that the lateral limls ri'iiiaiii dnniiaiit until dctaciied 

 fi'om the parent cdnn, and that fmir year old luids at the end of their 

 fourth season are attached imt to the corni Imt to the disorirani/.in.!^ cork 

 fragments at its base. 



An examination of the internal sirncture of mature coi-ms at different 

 times in a .lirowing season shows the folloAving features. At the begin- 

 ning of growth in March tlie starch-filled parenchyma is a homogenous 

 mass. "N^'hen the tiowers and leaves are just above ground a lower region 

 of tlie parencliyma, corresponding to tlie four year old porti(Ui. shows situs 

 of softening, becoming more translucent and containing less starch. As 

 the season progresses tliis condition of change increases until at or soon 

 after the time of fertilization of the tiowers, there is little but disorgan- 

 ized parenchyma and scattered vascular strands in the oldest pcu'tion. 

 Examination with the microscope at this time will show that a complete 

 separatoi'y layer of phellogen has been formed so as to extend betwetMi 

 the three and four year old portions, cutting off the older and protecting 

 the younger with a layer of cork cells. 



The formation and growth of A. triphyllum corms is greatly influ- 

 enced by food and climate. The variation in size of mature corms may 

 verj' i)roi)ably lie the direct result of these influences. Certain it is that 

 soiue corms lie dormant one year or longer and then grow vigorously 

 Then again conditions might require an extra amount of reserve food for 

 the perfection of fruit in stmie unfavorable season and so shorten the tim ■ 

 of some growth zones. In the ma.iority of cases, barring very unusual con- 

 ditions, regardless of the number of years since the germination of tlie 

 seeds from which they sprung or since their separation as lateral buds 

 from mature corms. the underground stems of A. triphyllum are four 

 years old. 



