ACACIA SEEDLINGS. 



145 



first mentioned plant, however, there have been nearly as 

 many examples with only one pinnate leaf as with an 

 opposite pair, so this species appears to be near the middle 

 of. a transition stage. 



Number of Pinnae on One Leaf. 



In addition to the records given in Parts III (393) and 

 IV (411) relating to the number of pinnae on one leaf of a 

 phyllodineous Acacia, the following are now added : — A. 

 poclalyricefolia and A, elongata may have two pairs, A. 

 accola four, A. implexa five, and A. melanoxylon eight pairs. 

 Divided Leaflets. 



On various species from time to time a pinna may be 

 found having one or more divided leaflets. Portions of the 

 lamina on either or both sides of the midrib, usually of a 

 basal leaflet, may be divided into one or several tiny leaflets, 

 the divisions in the lamina extending to the midrib of the 

 main leaflet. The feature may be seen on leaves of Acacia 

 aspera (Fig. 1), A. Farnesiana (Fig. 2), A. Oswaldi, A, 

 podalyrioe folia (Fig. 3), and A. tetragonophylla. In one 

 instance, in the case of A. podalyriodfolia the basal pair of 

 leaflets on an axillary leaf were transformed into two 

 simply pinnate leaves, the original midrib in each case 

 being substituted by a rachis (Fig. 3). 



Fig. l. 



Acacia aspera. 

 Divided Leaflets x2. 



Fig. 2. 



Acacia Farnesiana. 



Divided Leaflets. x2. 



Each pinna had seven 



pairs of leaflets. 



Fig. 3. 



Acacia podalyriwfolia. 

 Divided Leaflets, x 2. 



J— November 5, 1919. 



