NATURAL SCIENCES OP PHILADELPHIA. 155 



inch, broad ovate. Scales half the length of the tube, brown, with white 

 margins. 



14. Tube under half inch, thick, perfectly cylindrical ; segments quarter 

 inch, broad linear, and rounded at the apex, waxy white. Scales quarter inch 

 long, brown, with membranaceous margins. 



15. Tube full three-quarters inch, cylindrical ; segments quarter inch, tri- 

 angularly ovate, pale rose. Scales half inch, narrow and drawn out to an 

 awn-like point. 



16. Tube half inch, cylindrical. Scales less than one-sixteenth of an inch, 

 broad ovate, green, and barely pointed. 



On again examining No. 12, after making these notes, I was surprised to 

 find no trace of stamens, but with the pistil perfect ; and on examining the 

 other specimens I found three out of the fifteen were pistillate also. Another 

 remarkable fact was that all these i)istils had the fine cleft stigmas strongly 

 recurved, exposing a glutinous surface; while the hermaphrodite ones kept the 

 apex of the pistils closed. The ovaries of the pistillate forms were also evi- 

 dently better developed than those in the hermaphrodite condition, and the 

 inference was that the plant was practically dioecious. 



On the third of May I returned to the locality and found this hypothesis in 

 all probability correct. The pistillate plants were in proportion about one- 

 third that of the hermaphrodite, and could be readily distinguished after the 

 flower had faded by the recurved stigmas above noted. All the plants that 

 had shed their corollas were pistillate ; the apparently hermaphrodite jjlants 

 having their corollas dry on the receptacles from which it was not easy to 

 separate them — the scales of the calyx and a part of the stem coming away 

 with them. This is so well known a feature of impregnation in the develop- 

 ment of a fruit, that I need not dwell much on the importance of this fact, as 

 showing the fertility of the pistillate, and the sterility of the opposite form. 



I engaged friends to furnish me specimens from other places. Dr. James 

 Darrach finds them, as I have above described, in another locality on the Wis- 

 sahickon. Miss Anderson sends me ten specimens from Edge Hill, Mont- 

 gomery County, Pa., amongst which two are purely pistillate, the rest varying 

 much as in the Wissahickon specimens. Mr. Isaac Burk finds pistillate plants 

 abound at Mount Ephraim, New Jersey, but there are abortive filaments with- 

 out anthers, and he sends me one specimen of this character. Mr. Charles E. 

 Smith sends me a dozen or so specimens from Haddonfield, hermaphrodite, 

 and so exactly alike that they probably all come from one plant. Mr. E. Dif- 

 fenbaugh sends ten specimens from another place in New Jersey, all with 

 anthers, but varying from nearly no filaments to filaments three-eighths of an 

 inch long ; varying also in the proportionate lengths of scales, tubes and seg- 

 ments ; but not near as much as in tiie Wissahickon specimens. Prof. Cope 

 sends samples from Delaware County, Pa. These are varied like the Wissa- 

 hickon ones ; and Mr. Cope remarks to me that the pistillate forms are so dis- 

 tinctly characterized, by the vasiform recurved corollas and other characters, 

 that he can readily distinguish them as he walks along. 



Has this peculiarity of Epigcea repens been overlooked by the many botanists 

 who must have critically examined it heretofore? Or has the plant reached a 

 stage of development when germs of new forms spring actively into life ? 



In a paper on Lopezia, published in the last volume of the Proceedings, I 

 showed that the sexual organs of that genus were admirably arranged to pre- 

 vent the pollen of a flower falling on its own stigma. This behavior of Epiyxa 

 adds another to the list of plants, now so extensive, known to have an ab- 

 horrence of self-fertilization. It may not be out of place to hazard a reason 

 for this course : 



There would seem to be two distinct principles in relation to form going 

 along together with the life of a sjiecies. The tendency of the one force is to 

 preserve the existing form ; the other to modify, and extend it to newer chan- 

 nels The first we represent by the term inheritance, the other we understand 



1868.] 



