236 MANUAL OF TROPICAL AND SUBTROPICAL FRUITS 



bulletin by Higgins and Holt), but the importance of these is 

 lessened by the fact that during the lifetime of a plant it may 

 change from one form to another. 



In general, it may be said that plants which develop from 

 the seed as pure pistillates will retain their sex without modi- 

 fication, but plants which commence life as pure staminates may 

 undergo a change of sex. It has been asserted that a change 

 of sex may be induced by topping the male tree or breaking its 

 roots. M. J. lorns, who studied this question in Porto Rico, 

 reached the conclusion that other conditions than the loss of 

 the terminal bud must be present to induce a change of sex, 

 and he suggested that the trees may pass through definitely 

 recurring cycles of development, and be subject to the change 

 only at certain periods. L. B. Kulkarni, 1 who investigated 

 the matter in India, came to the belief that change of sex is 

 not in any way connected with the removal of the terminal 

 bud. He found that male plants, in the course of their develop- 

 ment, may present a number of different sex-combinations, as 

 follows : 



First stage : Staminate flowers only. 

 Second : Staminate, with a few hermaphrodite flowers. 

 Third : A few staminate, with many hermaphrodite flowers. 

 Fourth: A few staminate, with many hermaphrodite, and a few 

 pistillate flowers. 



Fifth : Hermaphrodite flowers only. 

 Sixth : Hermaphrodite, with a few pistillate flowers. 

 Seventh : A few hermaphrodite, with many pistillate flowers. 

 Eighth : Pistillate flowers only. 



Thus the plant in the course of its life history may change from 

 a staminate to a hermaphrodite and then to a pure pistillate. 



At the Hawaii Experiment Station, much attention has been 

 devoted to breeding papayas. Some of the objects in view 

 have been hermaphroditism (in order to eliminate the necessity 



1 Poona Agrl. College Magazine, 1, 1915. 



