538 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



Vines (44) on page 17 of his Textbook on Botany states: "One of 

 the most remarkable instances of an intercalary growing-point is 

 that occurring in connection with the development of hollow, more 

 or less tubular structures {e. g., inferior ovaries, 'calyx- tube' of 

 Rosaceae, gamopetalous corollas, inflorescence of the fig, pitchered 

 leaves of Nepenthes, Utricularia, etc.). Taking the case of a 

 hollow floral receptacle (whether inferior ovary or 'calyx-tube') 

 when the apical growth of the axis is arrested, a zone of embryonic 

 tissue lying close behind the apex gives rise to a projecting ring 

 of tissue, which by continued basal growth, becomes a tube en- 

 veloping the apex of the shoot." And again on page 495: " In a 

 great number of plants the perianth and androecium are raised by 

 the intercalary growth of a lower portion of the axis (as repre- 

 sented by the outer portion of the torus) and stand on a circular 

 rim surrounding the apex of the axis which lies at a lower level. 

 Of this condition two different forms occur: in the one, the carpels 

 are inserted in the depression at the apex of the axis, and there 

 form one or more ovaries free from it, primarily at least, though 

 they may subsequently become adherent to it; in such cases as in 

 the rose and apple, the flower is said to be perigynous." 



Goebel in describing the development of the fruit in the apple 

 states that an ordinary perigynous flower would develop if the 

 carpel alone, by intercalary growth produced the ovary. He 

 attributes the formation of the ovarian cavity to growth involving 

 "both the flower axis and the base of the carpels which quite 

 cover its insides."^ 



The growth of the carpel in the apple as an established organ 

 has no relation to the further growth of the structure which pro- 

 duced it, save as they may develop conjointly. Intercalary 

 growth occurs in both simultaneously. Following then the 

 principles elaborated by Van Tieghem and the various examples 

 given by other authors, intercalary growth may be distinct with 

 the interpolated tissue clearly limited by zones of mature tissue 

 or it may occur with terminal growth and according to either the 

 simultaneous or successive development complex growth relation- 

 ships result. The development of the flower of the apple is the 

 result of both terminal and intercalary growth. The excessive 

 growth resulting in the fruit is due chiefly to the intercalary growth 

 of the torus. 



' Page 568. 



