190 



THE GARDEN MAGAZINE 



December, 1912 



only knows the individual, and all her 

 efforts are concentrated on fitting the 

 individual to its little niche and environ- 

 ment. If nature was a blind force, this 

 might be true, but we doubt that. How 

 did they arrive ? 



The origin of so many forms inside one 

 genus is difficult to account for, and raises 

 the debatable question of the origin of 

 species. That these hawthorns are of 

 hybrid origin can hardly be entertained at 

 all. The progeny of hybrid parents is 

 always known to be very heterogeneous in 

 its characters, and this of course must be 

 expected in the combination of two specific 

 types in seminal offspring. I myself have 

 collected and studied hundreds of species 

 throughout Western New York, and from 

 London, Ontario, Canada, to Prescott on 

 the St. Lawrence River, and perhaps the 

 largest number of species found grouped 

 together is on the Rumsey estate, on the 

 east side of Buffalo, beside Delaware Park, 

 where on a few acres thirty-five species 

 grow spontaneously, and in many instances 

 in dense thickets, with their branches inter- 

 mingling, and every opportunity for cross 

 fertilization occurs. In the raising of the 

 seedlings, however, there is nothing to show 

 that this has happened. The question then 

 of hybrid origin may be dismissed. 



It has been suggested by some observers 

 that they may be mutants. This is based 



on the theory of the origin of species, by 

 Professor de Vries, botanist, of Amsterdam, 

 Holland. According to this view, species 

 appear suddenly and are stable and con- 

 stant, if conditions are favorable, from the 

 moment they arise. Let us cite a specific 

 case to further illustrate our understanding 

 of this view : Crataegus pedicillata is a very 

 common arborescent species in the Genesee 

 Valley, in the FlabeUatae group. It has 

 seven to ten stamens, with rose colored 

 anthers and lax, pubescent corymbs. The 

 fruit is short, oblong, depressed at the inser- 

 tion of the pedicel, bright lustrous red, 

 with soft reddish pulp, three-fourths of an 

 inch long, and half an inch thick. Leaves on 

 fertile and vegetative shoots always round 

 at base. I have raised hundreds of seed- 

 lings from this species and I have not ob- 

 served the slightest deviation from the 

 above specific characters in any of the 

 progeny, in leaves, flowers, or fruits. There 

 is no evidence of mutation, and if mutation 

 accounts for these numerous species, when 

 did it take place, and why cannot we see it 

 going on now? Again: Cratagus Duro- 

 brivensis is a very common species in the 

 Genesee Valley, and widely distributed. 

 The large, smooth, clustered blossoms, with 

 twenty stamens, rose anthers, and globose 

 to sub-globose fruit, lustrous red, with 

 stout triangular calyx lobes, which ripens 

 in October, and hangs on without loss of 



color until early winter, always shows the 

 same definite characters, and the progeny 

 display the same faithfulness to type. 

 As I understand the theory of mutation it 

 does not account for these species as there 

 is nothing to show that hidden generative 

 forces are at work producing new species, 

 that appear instantaneously. 



I am therefore inclined to believe the 

 concept of Charles Darwin in regard to 

 the origin of these species of American haw- 

 thorns and all plant species that "natural 

 selection acting only by the preservation 

 and accumulation of small inherited modi- 

 fications," and extending over a long period 

 of time, and so slowly perhaps, that any 

 change is hardly perceptible in a man's 

 life time, and is the only correct explana- 

 tion for the appearance of these species 

 and all other species. 



There is one further remarkable phe- 

 nomenon however in regard to the American 

 hawthorns. It is a well known fact, in horti- 

 cultural experience, that the different spe- 

 cies in some genera of plants intercross and 

 hybridize freely. For example, Philadel- 

 phus, Malus, and Berberis get badly mixed 

 up if a number of the different species are 

 planted together. The species cannot be 

 depended on to come true from seed, if 

 grown in proximity to each other. There- 

 fore, that the hawthorns show no inclination 

 to intercross, even in the species of the 



As lawn trees the hawthorns are almost equally attractive in winter with their sturdy much branched limbs IC. conlata) 



