Origin of Species and Varieties 591 



swarm of elementary species, while the original 

 strain might even now be still in a condition of 

 mutability. A close scrutiny in the native re- 

 gion is likely to reveal many unexpected 

 features. 



A very interesting novelty has already been 

 described in a former lecture. It is the Xan- 

 thium Wootoni, discovered in the region about 

 Las Vegas, New Mexico, by T. D. A. Cockerell. 

 It is similar in all respects to X. commune, but 

 the burrs are more slender and the prickles 

 much less numerous, and mostly stouter at their 

 base. It grows in the same localities as the 

 X. commune, and is not recorded to occur else- 

 where. Whether it is an old variety or a recent 

 mutation it is of course impossible to decide. 

 In a culture made in my garden from the seed 

 sent me by Mr. Cockerell, I observed (1903) that 

 both forms had a subvariety with brownish 

 foliage, and, besides this, one of a pure green. 

 Possibly this species, too, is still in a mutable 

 condition. 



Perhaps the same may be asserted concerning 

 the beautiful shrub. Hibiscus Moscheutos, ob- 

 served in quite a number of divergent types by 

 John "W. Harshberger. They grew in a small 

 meadow at Seaside Park, New Jersey, in a 

 locality which had been undisturbed for years. 

 They differed from each other in nearly all the 



