584 Mutations 



Intermediate forms have not been met with. 

 Some slight reversions may occur in the autumn 

 on the smallest and weakest lateral branches. 

 Such reversions, however, seem to be very rare, 

 as I have tried in vain to produce them on large 

 and richly branched individuals, by applying all 

 possible inducements in the form of manure 

 and of cutting, to stimulate the production of 

 successive generations of weaker side branches. 



This constancy was proved by the experi- 

 ments of Solms-Laubach, which I have repeated 

 in my own garden during several years with 

 seed received from him. No atavists or deviat- 

 ing specimens have been found among many 

 hundreds of flowering plants. 



It is important to note that within the family 

 of the crucifers the form of the capsule and the 

 attributes of the valves and seeds are usually 

 considered to furnish the characteristics of 

 genera, and this point has been elucidated at 

 some length by Solms-Laubach. There is, how- 

 ever, no sufficient reason to construe a new 

 genus on the ground of Heeger's globular- 

 fruited shepherd's purse; but as a true elemen- 

 tary species, and even as a good systematic 

 species it has proved itself, and as such it is de- 

 scribed by Solms-Laubach, who named it in 

 honor of its discoverer. 



Exactly analogous discoveries have been 



