34 



BOTANICAL GAZETTE 



[JULY 



case was found in the sand at Miller, Indiana, shown in fig. 5. 

 A 3-year-old specimen (b) grew within the field of such a layer, and 

 the effect is seen in its well developed horizontal laterals. The 

 carbonaceous layer in question was absent in the neighborhood of 



Fig. I Fig. 2 



Figs, i, 2. — Prumis ptimila: fig. i, 3 months old; fig. 2, 3 years old 



Fig. 3. — Primus prnnila, showing asymmetric habit 



