1885.] 



AND HORTICULTURIST. 



19 



change in the relative length of stamens and 

 pistils, which I have here pointed out ? I think 

 that such will prove to be the fact. [The Editor 

 does not remember, nor has he the opportunity at 

 hand to examine.] 



At the close of my paper, I requested the co-op- 

 eration of all the botanists of the society in an effort 

 to detect and report such examples of flowers_ 

 whether of the garden or the wilds, as really or 

 apparently, militated against the propositions pre- 

 sented in my paper. The result has been, I think, 

 that all or nearly all of them are satisfied that the 

 propositions are true. Buffalo, N. V., Dec. 6. 



ON RAPID CHANGES IN THE HISTORY OF 

 SPECIES. 



BY THOMAS MEEHAN. 



At a recent meeting of the Academy of Natural 

 Sciences of Philadelphia, Mr. Meehan exhibited 

 flowers of a remarkable Halesia, and remarked on 

 the wide divergence reached without any inter- 

 vening modifications from the original, and ob- 

 served that it was another illustration of what he 

 thought must now be generally accepted, that the 

 maxim of Ray, natura nonfacit saltiim, itself need- 

 ed modification. He had called attention to this 

 particular departure among others in a paper be- 

 fore the " American Association for the ad- 

 vancementof Science " in 1874.* What he de- 

 sired to do now was to emphasize a few 

 of the points brought out prominently in that 

 paper, that " variations in species as in morphologi- 

 cal changes in individuals, are by no means by 

 gradual modifications,— that suddenly formed and 

 marked variations perpetuate themselves from 

 seed and behave in all respects as acknowledged 

 species, and that variations of similar character 

 would appear at times in widely separated locali- 

 ties." 



In addition to the illustrations given in that 

 paper, a remarkable one was afforded by the Rich- 

 ardia /Ethiopica, the common Calla of gardens 

 the present season. Some four inches below the 

 perfect flower a mere spathe was developed, par- 

 tially green, but mostly white as usual ; but in this 

 case we do not call it a spathe, but a huge bract. 

 In other words the usually naked flower scape of 

 the Richardia, had borne a bract. Flowers with 

 a pair of more or less imperfect spathes were not 

 uncommon in some seasons. The peculiarity of 

 the present season was the interval of several in- 



*See Proc. Am. Ass. Ad. Science, vol, 2-3, B. 9. 



ches on the stem, which justified the term of bract 

 to the lower spathe. From the vicinity of Phila- 

 delphia, numbers had been brought to him, and 

 others had been sent from Ohio, Indiana and 

 Illinois, — some hundreds of miles apart. What 

 was the peculiarity in this season over others 

 which induced the production of this bract.' 

 was one question. Whatever it may have been 

 it operated in bringing about a change of char- 

 acter without the intervention of seed, directly 

 on the plant, and in many widely separated 

 places at the same time. What is to prevent a 

 law which operates exceptionally in one season 

 operating again and in a regular and continuous 

 way ? So far as we can understand there can 

 be no reason, and, if it should, we have a new 

 species, not springing from seed, or one individual 

 plant, constituting one geographical centre of crea- 

 tion, from which all subsequent descendants emi- 

 grated and spread themselves, but a whole brood 

 of new individuals already widely distributed over 

 the earth's surface, and entirely freed from the 

 struggle for existence which the development of 

 a species from a solitary individual pre-supposes. 



Aside from the great value of this illustration 

 of how the whole character of a species might be 

 modified simultaneously over a wide extent of 

 country, it afforded a lesson in environment. Ex- 

 ternal circumstances may influence modification, 

 but only in a line already prepared for modifica- 

 tion. This must necessarily be so, or change 

 would be but blind accident, whereas paleontol- 

 ogy teaches us that change has always been in 

 regular lines and in co-ordinate directions, which 

 no accident has been able to permanently turn 

 aside. Just as in the birth of animals we find that 

 however powerful may be some external law of 

 nutrition, which, acting on the primary cell of the 

 individual, decides the sex, — yet we see that no 

 accident has been able to disturb the proportion 

 of the sexes born, which has always been, so far 

 as we know, nearly equal. So in the birth of 

 species, making all allowance for the operation of 

 environment, the primary plan has been in no 

 serious way disturbed. We have to grant some- 

 thing to environment in the production of new 

 forms, but only as it may aid an innate power of 

 change ready to expend itself on action as soon 

 as the circumstances favor such development, — cir- 

 cumstances which, after all, have very little ability 

 to determine what direction such change shall 

 take. 



We know that distinct forms do spring through 

 single individuals from seed, and that after bat- 



