Mutations in Horticulture 613 



thought to be lost, and the culture was given up, 

 as the Mendelian law of the splitting of varietal 

 hybrids was not known. According to our pres- 

 ent knowledge we might expect the atavistic de- 

 scendants of the first dwarf to be hybrids, and 

 to be liable to split in their progeny into one- 

 fourth dwarfs and three-fourths normal speci- 

 mens. From this it is obvious that the dwarfs 

 would have appeared a second time if the strain 

 had been continued by means of the seeds of the 

 vicinistic progeny. 



In order to avoid a return to this phase of the 

 question, another use of the vicinists should at 

 once be pointed out. It is the possibility of in- 

 creasing the yield of the new variety. If space 

 admits of sowing the seeds of the vicinists, a 

 quarter of the progeny may be expected to come 

 true to the new type, and if they were partly 

 pollinated by the dwarfs, even a larger number 

 would do so. Hence it should be made a rule to 

 sow these seeds also, at least when those of the 

 true representatives of the novelty do not give 

 seed enough for a rapid multiplication. 



Other dwarfs are recorded to have sprung 

 from species in the same sudden and unexpected 

 manner, as for instance Ageratum coeruleum of 

 the same nursery, further Clematis Viticella 

 nana and Acer campestre nanum. Prunus Ma- 

 haleb nana was discovered in 1828 in one 



