194 VEGETABLE ORGANOGJIAPHY. 



cellular zone ; it is composed of bundles of fibres, which 

 are more compact towards the circumference, and looser 

 in the centre of the stem ; and always surrounded by a 

 cellular tissue, which seems to replace the pith. It 

 does not increase in diameter after a certain given 

 period. But Liliaceas with branching stems present 

 singular phenomena : some, such as the Asparagi, pro- 

 perly so called, although very branching, do not increase 

 in diameter after their first development ; others, such 

 as Dracaena Draco, grow very much at the same time 

 that they branch. Du Petit-Thouars has observed that 

 when the Draccena shoots forth branches, each of them 

 at its first development produces fibres, which are inter- 

 posed, he says, between the cellular zone and the woody 

 body; — that of these fibres, those which are inferior 

 have a tendency to descend, and those which are directed 

 to the upper side quickly bend and descend as the pre- 

 ceding ; whence he concludes that the descending fibres 

 of these buds cause the increase in diameter of the 

 trunk. This very remarkable fact unfortunately cannot 

 easily be studied by European botanists, and as yet 

 remains unseen by us, especially if it be considered that 

 the branching Asparagi of our climate do not present 

 any resemblance to them. 



The ramifications of the Pandaneae have much affinity 

 with those of the Asparagi. I have before me a trunk 

 of Pandanus, in which is seen the origin of a branch. 

 It presents, as is usual in Endogens, a mass of longi- 

 tudinal fibres : the base of the branch, cut transversely, 

 has also the same appearance ; but the union of the two 

 bodies appears to take place, because the fibres of the 

 branch penetrate perpendicularly into the trunk without 

 anastomosing with the longitudinal ones, but cutting 

 them at right angles, so as to form a kind of netted 

 cross. I have said, in order to follow Du Petit-Thouars's 



