282 ' 



ME. D. MOKBIS OS THE PRODUCTION 



in Hyphcene, when it takes place, is said to be due, not to the 

 division of the apical region (which would be true dichotomy), 

 but to the occasional growth of " a single axillary bud, the deve- 

 lopment of which soon equals that of the parent axis, and causes 

 the deflection of the latter so as to give a forked appearance" *• 

 I am unable to verify this statement by reference to actual 



■ 



specimens; but by analogy it may be assumed to be correct. 

 A similar appearance of dichotomy is shown in the forked 

 specimens of Pandanus, Yucca, Vellosia, Agave, Aloe, and other 

 monocotyledonous genera. Sachs, in discussing the general 

 mode of branching in monocotyledons, says it "is always mono- 

 podial and usually axillary ; a bud is generally formed in the axil 

 of each leaf, but often does not unfold ; so that the number of 

 branches visible is often less than that of the leaves (as in Agave, 

 Aloe, Draccena,~Palms, &c.)"f. 



Asa Gray says, " dichotomy or a forking division of an apex 

 into two .... occurs rarely and exceptionally, if at all, in 

 phaenogams " 



+ 



Fig. 1. 



Longitudinal section of a branching stem of the Doum Palm, Hyghcsne thebaic a 

 (Kew Museum), a. Main axis. b. Fully developed axillary branch. 



Henfrey, ' Element. Bot.' (1870), p. 37. 

 t Sachs's - Textbook of Bot./ Engl, brand. (1875), p. 543 

 J ■ Struct. Bot/ p. 47. 



