2 BULLETIN 176, U. S. DEPARTMENT OF AGRICULTURE. 
The 9 classes are as follows: 
(1) Yellow, round. (4) Flesh colored, oblong. | (7) Rose or red, long. ) 
(2) Yellow, oblong. (5) Rose or red, round. (8) Violet colored. = 
(3) Yellow, long. (6) Rose or red, oblong. (9) Streaked (mottled). ' | 
2 
* 
The varieties included in class 1 are divided into ten sections, 
which section 2 is perhaps a representative example. 
Section 2.—Tubers yellow or white, round; flowers colored, often abundant; flesh | 
white; sprouts violet, more or less colored. 
One of the ablest attempts at group classification in this country is 
that of Kohler, who, in March, 1909, published the first results of his” 
studies on the classification of potato varieties. His grouping of the 
varieties is based upon the following points: (1) Characteristics of - 
vines; (2) shape of tubers; (3) color of tubers. 
Eleven groups were described in 1909, viz: 
(1) Tuberosum group. (7) Early Michigan group. 
(2) Rural group. (8) Milwaukee group. 
(3) Endurance group. (9) Russet group. 
(4) Seedling B group. (10) Ohio group. 
(5) Green Mountain group. (11) Early Market group. 
(6) Carman group. 
In a subsequent publication, April, 1910, Kohler retained the same 
number of groups, but submitted new names for four of them, his 1910 
list being as follows: 
(1) Tuberosum group. (7) Green Mountain group. 
(2) Wohltmann group. (8) Michigan group. 
(3): Rural group. (9) Russet group. 
(4) Endurance group. (10) Ohio group. 
(5) Factor group. (11) Cobbler group. 
(6) Sharp’s Express group. 
In many respects Kohler’s grouping is satisfactory, but one might 
question the advisability of giving to any one group the name ‘‘Tuber- 
osum.”’ If all of the cultivated varieties are to be regarded as belong- 
ing to Solanum tuberosum, a group of only a few varieties can not be 
considered as exclusively entitled to such a designation. Exception 
might also be taken to three of the 1910 groups—Wohltmann, Factor, 
and Sharp’s Express—which derive their group names from foreign © 
varieties. It would seem desirable that the type ine should be- 
one of American origin. | 
In 1912 Milward ® mentions three groups as foptoscntine distinctive — 
types. These he called the round-white, the long-white, and the Rose — 
groups. 
1 Kohler, A. R. Potato experiments and studies at University farm. Minn. Agr. Exp. Sta. Bul. 114, 
p. 311-319, 1909. 
Kohler, A. R. Potato experiments and studies at University farm in 1909. Minn. Agr. Exp. Sta. Bul. 
118, p. 90-100, illus., 1910. 
2 Milward, J. G. Commercial varieties of potatoes for Wisconsin. Wis. Agr. Exp. Sta. Bul. 225, p. 7, 
1912. 
