Harris: TERATOLOGICAL FRUITS OF PTELEA 587 
Fruits with two wings and two locules may have 0, I, or 2 seeds. 
For frequencies I found: 
DOGS Ce esata eee fs) I 2 Total 
POU eS stg ee ees ts) I 2 3 Total 
Frequencies: 3/4 Se 5k . 33 159 80 I5 287 
Of the 287 three-winged fruits, thirteen were possibly bilocular; 
the remainder were clearly trilocular. Perhaps in these apparently 
bilocular fruits the partition wall had simply broken down, but 
two wings may have developed on the backs of some of the 
carpels. 
For the mean number of seeds per locule we have: 
Two-winged, A =1.056. 
Three-winged, <A =1.268. 
But I lay no stress on the comparison, both because of the small- 
ness of the number of pods dealt with, and because the two-winged 
fruits sectioned were not gathered in proportion to the three- 
winged fruits from each individual tree, but were merely a random 
sample saved for another purpose. A detailed study of material 
so collected that the possibility of difference in fecundity of 
individual trees could not cast doubt on the results, might be 
profitable. 
CoLp SprRING Harbor, N. Y. 
Explanation of plate 17 
Diagrams of normal and abnormal fruits of Ptelea. Fic. 1; class 1. FIG. 2, 3; 
class 2, im tolo and in cross section. FiG. 4; class 4. Fic. 5-7; class 5, in toto and 
in cross section. Fic. 8, 10; class 8. FiG. 9, 11; class 9. 
