80 THE AMERICAN BOTANIST. 



Now that attention has been so forcibly directed to 

 the forms thrown off, by what we have been calling" 

 species, a new field for original work has been opened to 

 all plant students. It will need many and careful obser- 

 vations on a great number of species before the mutation 

 theory will be either proved or disproved. While annuals 

 and biennials, from the shortness of their span of life, are 

 likeliest to give the most results in the least time, it is- 

 doubtless in the forest that we shall find the most striking 

 instances. Many trees have an individuailty about them 

 that is lacking in lesser plants and this may be well set 

 down to mutation. Possibly, too, the many forms now 

 believed to be hybrids among the oaks, willows, etc., may 

 be of the same nature. Provided that a single seed en- 

 closes a plantlet with evolutionary tendencies, it only 

 requires to be germinated and brought to maturitj^ to 

 show through a hundred years what DeVries' primroses 



show through a single season. 



* * 

 » 



It maj^ be added in passing that the mutation theory is 

 likely to have a very practical bearing upon nomenclature 

 and species-making by showing us a way of testing the 

 specific validity of segregates from other species. If the 

 plant from which the new species is separated, can be 

 proved to be constantly producing such forms through 

 seed, it would seem that we are scarcely warranted in call- 

 ing the new form a species in the sense that the parent is- 

 This, also, suggests that if all the seed produced by a 

 single hawthorn tree were brought to maturity there 

 might be several surprises for workers with this genus. 

 We understand that Dr. Sargent has begun work of this 

 nature with the hawthorns, and others will no doubt 

 make similar experiments with the violets, blue-eyed 

 grasses and other variable genera. Ever\' person who 

 possesses a few square feet of ground and the patience and 

 time for such work can contribute materialh^ toward a 

 better understanding of plant evolution by careful obser- 

 vations along these lines. The merest botanizer has here 

 a chance to do original work of the greatest scientific 

 value and w^e hope* that many will undertake it. 



