Productiveness and Degeneracy of the Irish Potato 9 
profuse. The blossoms of No. 3 are usually abundant, and while the 
female parts appear to be well developed the stamens are incompletely 
developed, and do not bear pollen. No. 4 is like No. 3, but with great¬ 
er sexual development and a marked approach of the tuber toward 
that of No. 5, which bears abundant large seed-balls, with many and 
vigorous seeds. 
PLATE V. PEARL BLOSSOMS. 
Drawing by Miriam A. Palmer. 
Intermediate Forms have a green¬ 
ish yellow stamen, sometimes 
replaced by a hair, and always 
lacking in shape, color and pol¬ 
len. No. 3 vine. 
No. 5 Vine bears fertile blos¬ 
soms with full corollas and 
orange colored stamens, with 
abundant virile pollen. 
Conditions at Greeley .—The soil in this region, when well rotated 
with alfalfa, and especially when manured for a series of rotations, is 
exceedingly fertile, so that there are farms on which for years a yield 
of forty bushels of wheat per acre has been the minimum and where 
sixty bushels has been exceeded. As in most of the upper plains 
regions, there is a large element of adobe or gummy clay present in the 
major part of the soils of this district; and even when a part of sandy 
friable loams, this gummy ingredient is an adverse factor in the grow¬ 
ing of potatoes, especially under irrigation on lands rather too flat* for 
water to run without puddling the sides of potato hills. Thus, with 
conditions favoring soil diseases of the potato, it has been proven by 
long experience at Greeley that on the average farm very close and 
very deep cultivation is the most profitable. The region and its peo¬ 
ple co-operate well and this system when once worked out has been 
applied to all lands alike, even where greater slope and more open 
soil make so rigid a system less desirable. 
*See in Bulletin 175, Irrigation, Potato Diseases and Cultivation. 
