MISCELLANEOUS NOTES. 381 



haardunnen, einfachen Verzweigungen ; sie entspringen reclits unci links an 

 jeder Blattnarbe und erscheinen dadurch gegenstandig. Mitunter ent- 

 wickeln sich an denselben Stellen auch einfache lange Wurzelfasern in 

 Mehrzahl. 



Professor Blatter objects to these bodies being called " Pectinate " organs. 

 I agree with him and I have here designated them as ramified roots instead. 

 Root caps have been noticed by me in some rosettes. These caps tipped 

 every ramification, and also the main axis. I further noticed that several 

 simple or occasionally biramous roots also arose in some cases from the 

 same nodes which gave rise to the ramified organs. 



Every node is provided with a simple undivided leaf of some kind or 

 other. The ramified structures arise on either side of a leaf or a leaf scar 

 from the stem. Moreover in position and origin they agreed completely 

 from morphological as well as anatomical points of view with the other set of 

 undoubted ordinary simple roots. 



Other plants have been known with dimorphic roots. Thus in the 

 climbing Aroids there are the climbing roots and feeding roots both arising 

 adventitiously from the stem, Nor are examples of roots with chlorophyll 

 wanting, if we turn to the classes of Orchids and Lemnas. Finally, the 

 formation of extensive net- works of roots by aquatics or semi-aquatics is a 

 matter of common observation.* 



In I])omoea aquatica we get precisely a pair of such ramified roots 

 restricted to the nodes and situated on either side of the leaf. 



H. M. CHIBBEE. 



Agriculitjral College, Poona, 

 June 1914. 



No. XLIIT.— ON LEAF-FALL, 



{With a plate.) 



Kerner in his Natural History of Plants f has this interesting observation 

 on fall of the leaf : — " It is also worthy of remark that in some trees the 

 leaf-fall begins at the end of the branches and gradually proceeds towards 

 the base, while in others the contrary is the case." Our local roadside 

 trees afford interesting subjects of study from this point of view. Here 

 (Fig. 1) is a Nim tree {Azadirachta indica, A Juss). We find the old leaves to 

 still occupy the crown while the rest of the tree presents its skeleton in 

 full view. The contrasting portions are not the base and the end of 

 branches as observed by Kerner, but the base and the end of the tree as a 

 whole. The phenomenon is obviously correlated not with any question of 

 position, whether at base or apex, but with the question of the external 

 factors surrounding the aerial parts of the entire plant. Insolation and 

 humidity to which the crown is exposed are different from those to which 

 the rest of the plant is exposed. 



It may be that these persistent old leaves help the new leaves on the 

 lower part of the plant to come out without any danger from the sun 

 (Fig. 2). When these new leaves have established themselves, the old 

 leaves disappear from the crown and are replaced by new leaves which in 

 turn are protected from scorching by increased humidity brought about by 

 the vigorous transpiration going on in the rest of the plant. 



The Tamarind [Taynarindus indica, Linn). Supplies another interesting 

 subject for the same study. Here the leaves that persist to the last occupy 



•Natura] History of Plants by Kerner and Oliver* I, 752-3. 

 t Kerner and Oliver > I. 361. 



