4 
Colorado Experiment Station 
versdy proportionate to the sexual development of the plant; that 
the most degenerate tuber is grown by the plant which carries fully 
developed flowers and virile pollen; while those plants on which only 
the female portions of the flowers appear to be fully developed pro¬ 
duce tubers intermediate in form and yield, and that the best tubers 
and the largest yield are produced by the type of plant whose buds 
do not even swell. 
Practical Bearings .—The way is opened to study out: 
1. What conditions insure productive seed potatoes. 
2. How to grow potatoes free from defects. 
3. What are the best changes of seed potatoes, and why. 
4. How best, if way there be, to grow Pearl seed potatoes without 
change. 
Additional light may be secured thereby on all problems of plant 
production where the seed is not the desired end. 
occasional stem nodes, and which tints the underground part of the main 
stems, is alike in the three sorts,—deep in the Blue Victor, and faintly pink 
in the others. 
We go minutely into the characteristics of these three sorts because 
it is essential to our reasoning that the varieties are one, with three sorts of 
color; while the corresponding degrees of tuber degeneracy occur in the 
three colors and therefore cannot be confounded with the chance intro¬ 
duction of tubers of other varieties. 
Alike, among the three varieties, we find the same ideal types, the same 
average tubers, and the same degenerate forms. With tubers Nos. 4 and 5, 
Plate IV, there is a change to a lighter color—a phenomenon not yet under¬ 
stood. In the Blue Victor, the “bastard” form is lighter pink than the 
others; among Pearls, the bastards are whiter and more waxy in color, 
while in the People’s variety, the bastard forms, when placed beside Pearl 
bastards show the deeper brown shade that is a characteristic difference 
betwen the varieties. 
The term bastard is one employed by growers and is herein used to 
mean a certain degenerate form of tuber of the Pearl family. 
Environment of Plants Observed. —The writer has had experimental 
plots at elevations of 3500, 4000, 4500, 4800, 6500, 7000, 7800,, and 8100 feet, 
and on soils ranging from light sand to clay loam, and with fertility vary- 
from the limited nitrogen and humus content of lands never yet deeply 
moistened by nature and. supporting only scant buffalo grass or scantier 
sage brush, to that of irrigated alfalfa lands perhaps unexcelled in natural 
fertility and nitrogen content. See Bulletin 175 of this station for a dis¬ 
cussion of The Potato Industry of Colorado. 
The Solution of a Leading Problem of one of the most highly specialized 
of farming communities is herein sought for the sake of that community 
a rt° • P ° tat ° T dustry - T be study is founded upon the previous work 
of the Station and. is an out-growth of that spirit at Greeley which makes 
potatoes and the intricate problems of potato growing the leading topic 
wherever farmers get together, whether at the open meetings of the 
wom - s c °u n try clubs, or when neighbors talk over the fence in the field. 
M ° th ?£ ? f the . Pearl —Peerless, White Victor, Valley Prize, 
^ Vhlte PearI > and - ln th e opinion of Sutton & Sons, the Puritan, of 
Great Britain. Of the Peoples— Polaris, People’s Party. 
