186 REPORT OF THE DEPARTMENT OF BOTANY OF THE 
der seeds per pound was determined. The numbers, given in the 
order of their size, are as follows: 
2 8 16 25 38 58 990 162 270 892 
2 1 16 20 39 60 100 174 25% 972 
2 “II 17 27 40 62 100 176 278 1123 
3 12 17 28 44 62 102 182 309 8652 
4 12 18 32 44 605 105 189 320 22996 
4 13 20 33 45 65 108 190 321 
5 14 21 34 46 65 119 192 4378 
6 14 21 34 47 67 127 194 489 
6 14 21 34 52 68 129 197 645 
'g 15 22 35 53 73 138 198 = 672 
7 15 22 36 56 76 141 227° 735 
8 16 23 a7 57 77 143 232 =744 
8 16 23 37 V4 82 156 234 870 
Several different species of dodder infest alfalfa, but how many of 
them are represented in the above-mentioned samples is not known. 
The identification of the different species by their seed characters 
being somewhat difficult, the writers have not attempted it. It ap- 
pears that for all practical purposes it makes little difference to 
what species the dodder belongs except that the seed of some 
species, being larger than that of others, is more difficult to remove 
by sifting. (See page 194.) Accordingly, the writers place them 
all in two classes, small-seeded dodders and large-seeded dodders?’, 
(See Plate XVII, figs. 3 ‘and:4.) Inthe samples analyzedyerne 
small-seeded kinds of dodder greatly predominated. 
Most of the dodder-infested samples belonged to the poorer 
grades of seed, but some of them were decidedly high grade in all 
respects except that they contained dodder. Seed may be of good 
color, high purity and high-priced yet contain enough dodder to 
make it unfit for use. Even the so-called recleaned seed is not 
entirely reliable as regards freedom from dodder. 
However, the use of dodder-infested seed does not necessarily 
result in a dodder-infested crop. Probably, the great majority of 
dodder seeds fail to make plants. In the spring of 1906 the writers 
> Hillman (46) distinguishes five principal species of dodder occurring in 
alfalfa seed; viz. Cuscuta epithymum Murr. (clover dodder), C. planiflora 
Ten. (small-seeded alfalfa dod‘er), C. arvensis Beyrich (field dodder), C. 
indecora Choisy (large-seeded alfalfa dodder) and C. racemosa chileana 
Engelm. (Chilean dodder). The first two have small seeds, the last three, 
large ones. Hence, the term “small-seeded dodders” as used by the writers 
includes Hillman’s first two species while the other three are classed as 
“large-seeded dodders.” 
