EXPERIMENTS WITH POTATOES. 
13 
The superphosphate plat had vines nearly as vigor¬ 
ous as the latter, but fell far short in yield of tubers. 
The plaster plat gave the second best yield, but bore 
vines of only moderate vigor. 
• The experiment needs to be tried more fully and 
elaborately than has yet been possible here. The experi¬ 
ment would seem to show a slight advantage from the 
use of plaster, a very decided advantage for bone meal 
and but little gain for the other two. 
THE WILD POTATO—CROSSES. 
We have grown one of the native potatoes of this 
State ( Solarium Jamesii) for the past two seasons. It did not 
prove fertile, however, until this season, which was due to 
our having grown it in rich soil. In procuring tubers of 
this species from the Montezuma valley last spring, a 
form with blue flowers and of compact habit of growth 
was secured at the same time, which has since been iden¬ 
tified by Prof. Coulter as Solarium Tuberosum var. boreale, 
not hitherto supposed to be indigenous to Colorado. 
From J. PI. Gregory we purchased another wild potato, 
which the same authority pronounces S. Jamesii. Having 
grown these three forms side by side the past season, and 
under exactlv similar conditions, we fail to see more than 
a general resemblance between the two, and both are 
very distinct from S. Tuberosum, var. boreale. In fact, 
neither would be recognized as a potato at all except by 
a botanist. 
We have succeeded in obtaining two seed balls of 
S. Jamesii, three of S. Species, and eleven of S. Tuberosum 
var. boreale , pollenized by cultivated varieties, and three 
of the cultivated varieties Morton White and Kuby, pol¬ 
lenized by S. Jamesii. 
Over two hundred crosses were made, S. Tuberosum 
var. boreale setting fruit freely when pollenized by the 
cultivated varieties, but our efforts to make some of the 
latter the seed parent when fertilized by this indigenous 
form, were not successful. 
