JlHiT 17, 1914] 



SCIENCE 



81 



peloriated toadflax and that of the double 

 variety of the corn marigold. These vari- 

 eties appeared in my cultures all of a sud- 

 den, after a number of years, the one in about 

 half a dozen of individuals in successive 

 generations, the other in a single instance. 

 The ordinary toadflax has only one spur on 

 its flowers and remained so in hundreds of 

 individuals until a single specimen bore 

 five spurs on every one of its flowers. The 

 corn marigold had normal flower heads 

 until 1899 when one individual produced 

 some slight signs of duplication. Next year 

 all its descendants bore double flowers and 

 the race showed itself constant from the 

 very beginning. 



Thus, the production of varieties by leaps 

 and jumps may be considered as a well- 

 proved fact in horticulture and in a state of 

 nature. It is a firm basis for a new theory, 

 and we have only to transport the prin- 

 ciple from the varieties to the origin of 

 elementary species. Recognized for species, 

 the theory will obviously be true for genera 

 and families also, and explain the evolu- 

 tion of all organic beings in all the differ- 

 ent lines of the genealogical tree. 



The idea of the origin of species by leaps 

 and jumps has the great advantage of an- 

 swering in an unexpected and decisive way 

 the numerous and in part very grave objec- 

 tions which have been brought forward 

 against the theory of Darwin. To my mind, 

 this is one of the best arguments in its 

 favor. It releases the theory of evolution 

 from the serious difficulties which its ad- 

 versaries have never ceased to urge against 

 it. Therefore it seems useful to give a brief 

 survey of them now. 



The oldest and most serious objection is 

 based on the obvious uselessness of new 

 characters during the first stages of their 

 evolution, if this is supposed to be invisibly 

 slow. Imperceptible odors can not guide 

 insects in their visits to flowers and assure 



to these a sufficient advantage in the 

 struggle for life. Adaptations for the cap- 

 turing of insects by plants would be of no 

 value in a primary and imperfect condition 

 and therefore can not be evolved by the 

 action of natural selection. Imperfect in- 

 stincts would be rather obnoxious, according 

 to Wasmann, and thus would be liable to be 

 destroyed instead of increased by this 

 action. So it is in many other cases. Begin- 

 ning characters would always be too insig- 

 niflcant to be of any value in the struggle 

 for life. Evidently the principle of leaps 

 and jumps at once relieves us of the neces- 

 sity of this hypothesis. It does not admit 

 a gradual appearance of characters, but 

 assumes these to appear at once in the full 

 display of their development, and without 

 the aid of natural selection. 



The same holds good for useless char- 

 acters. The theory of Darwin can not 

 explain them. According to him, every 

 quality is developed exactly through its 

 utility, and useless properties should be 

 eliminated from the very beginning by the 

 struggle for life. But it is now generally 

 recognized that many beautiful differentia- 

 tions are in reality no adaptations at all, 

 and that their usefulness is at least very 

 doubtful. This, for instance, is the case of 

 heterostyly and of the likeness of the 

 flowers of some orchids to insects. The 

 theory of mutations has no difficulty with 

 useless and even with slightly prejudicial 

 characters. Arising by a sudden jump, they 

 may keep their place, provided only that 

 they are not in such a degree hurtful as to 

 prevent a normal development of the indi- 

 viduals. 



A third objection has been derived from 

 the studies of the celebrated anthropologist 

 Quetelet, who discovered the general law 

 of fluctuating variability. He introduced 

 the principle of studying every quality for 

 itself and of comparing the different 



