1916.] JEPSON: REGENERATION IN MANZANITA 11 



While the number of observations that have been made are not 

 sufficiently large or geographically extensive to warrant final con- 

 clusions, the results so far are interesting, and are here put on 

 record to draw out criticism and to stimulate further observations. 

 One set of observations in a given locality, however faithful and 

 accurate, cannot be regarded as entirely sufficient, because in other 

 genera of the chaparral stump-sprouting varies within a species. 

 This variation may be related to the age, vitality, soil situation of the 

 individual, or to some other cause, such as variation in the mutilat- 

 ing or destroying agent, fire or the axe. An excellent example of 

 such variation may be had from Ceanothus sorediatus. Ceanothus 

 is a favorable genus for comparison in the matter of stump-sprout- 

 ing, as many of its species are typical chaparral shrubs, In the Oak- 

 land Hills Ceanothus sorediatus (Jim brush) has been observed 

 to stump-sprout freely; on Mt. Tamalpais we have found it killed 

 outright by fire. While this difference in behavior in a single species 

 has thus far not been observed in any species of manzanita, ampler 

 records based on a wider range of observations, are desired. 



