396 BOTANICAL GAZETTE [NOVEMBER 
oases in otherwise barren country and may be compared with the 
kipukas in the a-a flows. Many remnants of the primitive flora 
are today making their ‘‘last stand” in these tiny areas where they 
are protected from wild livestock, the greatest enemy of the in- 
digenous vegetation. Finally, the conditions of shade and moisture 
Fic. 12.—Diagram illustrating formation of kipuka in midst of lava fields. 
are more likely to be favorable in the pits than on the exposed 
open lava flows, and the plants in the pits exhibit more normal 
growth forms than those in the open. 
Kipukas.—This Hawaiian word, meaning an oval hole or 
depression, is a convenient desiniating for small areas that, owing 
to minor topographical irregularities, have escaped being covered 
by the lava flows which surround them (fig. 12). The flow may be 
