No. 436.] LOCALIZED STAGES IN PLANTS. 245 



exactly with the characters seen in the seedling. In stronger 

 growths, however, the first leaves have five leaflets or even more. 

 The second in such cases usually have seven. 



Fig. 4 shows exceptionally well a scries of stages in early 

 spring growth. The first leaf has five leaflets, the second seven. 

 The third leaf which is in the axil of number r has eleven leaf- 

 lets ; the fourth, in the axil of number 2 has thirteen. Number 

 5 farther up the stem has fifteen, number 6 twenty-one. Num- 

 ber 7 which is not wholly unfolded shows that it will have many 

 more than the leaf preceding it. The specimen represented by 

 Fig. 4 was taken from one of the strongest growths found and 

 does not revert to the very first condition of the leaflets found 

 in seedlings or feeble growths, as that in Figs. 1, 2, and 3. In 

 Fig. 4 there would naturally be a stage between leaves 2 and 3 

 with nine leaflets. In the strong growths these intermediate 

 steps are very apt to be skipped by acceleration of development. 

 Such a stage however is found in specimens such as represented 

 by Figs. 2, 3 and 5. The similarity of the early spring growths 

 representing localized stages to the seedling representing direct 

 development is strikingly shown in such plants as this where the 

 number of leaflets may be actually counted. 



Potentilla tridentata Ait. Figs. 6-9. 



Seedlings of this plant were found in the spring about the 

 adult plant and were alike in 

 having the first nepionic leaf 

 trifoliolate, but differed in the 

 characters of the tip of suc- 

 ceeding leaves. The first nep- 

 ionic leaf has no distal notches 

 and is almost exactly like the 



