106 Harshberger—Statistical Information Concerning the 
The numbers marked by an asterisk show us, that as 
respects the number of seeds contained in any given capsule 
of a plant, the result of the act of fertilization has not been so 
successful. 
Xanthium canadense, Mill_—A count was made of the 
fruits of a plant (var. echinatum) at the seashore in sand 
which showed five well-developed fruits, and a plant growing 
in gravel near Philadelphia, which had 622 fruits. 
Yucca filamentosa, L. (Adam’s Needle).—This liliaceous 
plant is of considerable interest from a biological standpoint 
owing to its dependence upon the moth, Pronuba yuccasella, 
Riley, which passes part of its larval existence in the capsule 
of the plant feeding upon the seeds. The moth, previous to 
depositing its eggs in the soft ovary, pollinates the stigma by 
placing a ball of pollen from the same flower between the three 
stigmatic lobes. This insures the production of good seeds 
on which the larve feed. The following table gives the 
number of circular holes drilled by the larvz in leaving the 
capsule to descend to the ground, the number of good seeds, 
the number of seeds devoured by the larve, and the number 
of abortive seeds. There are two rows of seeds in each of the 
three locules of the capsule; a false partition present gives the 
impression that the capsule is six-celled. The fruit vessel is 
usually constricted in the middle through the irritation caused 
by the puncture made by the parent moth, so that it becomes 
more or less dumb-bell shaped. In the enumeration, the two 
rows of seeds in each cell are designated first side, second side. 
The ratio established is that of the fully formed, black seeds 
to the abortive seeds. By adding the seeds of normal appear- 
ance of the first two columns, lettered first and second sides, 
and subtracting the number of seeds devoured as well as the 
bad seeds of normal form not given in the table from the sum 
thus obtained, the figures for the last column of the table were 
obtained, giving the number of seeds capable of germination. 
Eight capsules were examined September 11, 1894, and the 
results tabulated, as follows: 
