434 TOWER, DARWINISM. 
in the favorable plot 7,197 seedlings and in the normal plot, 392 
seedlings. 
Another stock of seeds was gathered at Guadalupe in the autumn 
of 1905, and these with the 1904 lot were tested through 1905 —1908. 
In all, 10 additional tests were made on companion plots, the first 
largely eliminating disadvantageous accidental position and the second 
preserving natural conditions unaltered. The total result of 200,000 
seeds equally divided between the two types of location showed 
94,047 germinating in the favorable locations, and in the natural 
locations where all the accidents due to position were preserved, 
7,243 germinated. 
In 1904 about a litre and a half of seeds of Solanum hertwigtt 
were gathered at random near Cuernavaca over an area of about . 
three square miles and similar collections were made in 1905 and 
1906. These seeds were tested in precisely the same manner as 
in the preceding instances during the years 1905, 1906 and 1907 
on five pairs of plots. Some of the seeds were fresh, some a year 
old and some two years old, and although age makes some 
difference in germinating capacity, the results massed in a com- 
bined figure shows that in the favorable plots of 50,000 seeds, 
41,039 germinated; and in the normal type of plot, 2.479, showing 
as distinctly as in the tests with Solanum rostratum that survival 
depended entirely upon chance position. 
In 1905, seeds of Solanum lanceolatum were collected on the 
deserts to the east of, Tehuacan. This Solanum grows on the 
Tehuacan deserts and is subjected to most rigorous conditions of 
existence, so that I was interested to discover what reactions the 
seeds would show in the matter of survival. In September, 1905, 
two lots of 10,000 each were sowed as in previous experiments 
about four miles north of the Hacienda of Miahuatlan. A second 
sowing was made about four miles north of the Hacienda of 
Llyano Grande. The first two plots did not germinate in 1906, 
apparently for the reason that no adequate rains fell over the area, 
as none of the desert summer annuals appeared. Rains adequate 
to start the desert vegetation in the area caused the Solanum seeds 


