146 Heredity. 



that the hive-bee is the least variable of all domesticated 

 animals (Darwin, Variation, Vol. ii. p. 307). 



Darwin says ( Variation, Vol. i. p. 360) that he pro- 

 cured a hive full of dead bees from Jamaica, where they 

 have long been naturalized, and on carefully comparing 

 them under the microscope with his own bees, could 

 not detect a trace of difference. 



With plants it is well known to all cultivators that 

 forms which are highly variable as seedlings can be kept 

 perfectly true by asexual propagation, and we have Dar- 

 win's authority (Variation, Vol. ii. p. 307, and Vol. i. 

 p. 429) for the statement that while hardly a single plant 

 can be named which has long been cultivated and prop- 

 agated ~by seed that is not highly variable, the total 

 number of instances of bud variation is as nothing in 

 comparison with seminal varieties. 



This contrast is the more remarkable when we recollect 

 that in most of our cultivated plants the number of buds 

 which develop is thousands of times greater than the 

 number of seeds which give rise to plants. It is clear 

 that if the chance of variation were the same in both 

 cases the number of bud variations would be thousands 

 of times greater than the number of seedling variations. 

 If there were thousands of chances of seedling variation 

 for one chance of bud variation, the number of bud 

 varieties would still be equal to the number of seedling 

 varieties. 



The fact that with all this probability in their favor, 

 bud varieties are very rare as compared with seedling 

 varieties, shows that the chance of bud variation is al- 

 most infinitely small as compared with the chance of 

 seedling variation. 



While we cannot deny that variation may sometimes 

 occur in organisms produced asexually, I think we are 



