v.] VAN MONS' HYPOTHESIS. 143 



2. The causes of variation are a change in soil, 

 climate or temperature. 



3. Whenever a natural species of tree produces one 

 or many varieties, these varieties continue to vary al- 

 ways, if they multiply by means of seeds, without ever 

 being able to return to the primitive form. 



4. The source of all variation, which is transmissible 

 by sowing, resides in the seeds. 



5. The older a variety of fruit or other tree, the less 

 the seedlings vary and the more they tend to return 

 towards the primitive form, without being able ever 

 to reach that state ; the younger or newer the variety, 

 the more the seedlings vary, or, as we might say, the 

 better the variations are for the use of man. 



Another epitomist expresses Van Mons' theory as 

 follows : 



' ' In sowing the first seeds of a new variety of fruit 

 tree, one obtains trees necessarily variable, — for they 

 cannot escape this condition, — but they are less disposed 

 to return to a wild state than those coming from seeds 

 of an old variety ; and as that which tends towards the 

 wild state has less chance of being perfect, as measured 

 by our tastes, than that which remains in the open field 

 of variation [or tends to vary still further], it is, there- 

 fore, in the sowing of the first seeds of the most recent 

 varieties of fruit trees that we must hope to find the 

 most perfect varieties for our tastes." 



The student will observe that there is little in these 

 statements to challenge controversy, save only the last 

 or fifth law, — that seeds from old varieties tend to give 

 small differences in the seedlings, and that these differ- 

 ences are usually in the direction of inferiority, being 

 reversions toward the primitive type of the species; and 



