16 
Colorado Experiment Station 
TAIILK III. — SHOWING TOTAL NUMMKK OF ALL SPECIKS PASSINfi A 
GIVEN POINT ON A 12-FOOT DITCH DURING A PERIOD OF 24 HOURS 
No. of 
Specie.^ 
No. of Seeds Caught 
in 15 Minutes on a 
Surface of 314". 
Crogs-section 4.14". 
sq. inches 
No. of Seeds Passing a 
Given Point in 24 Hours 
on a 12 foot Surface. 
Cross-section, 234 
sq. inches 
Dates 
15 
191 
4,290,624 
6/ 5/1919 
18 
310 
6,963,840 
6/ 5/1919 
17 
99 
2,223,936 
5/17/1919 
21 
208 
4,672,512 
5/19/1919 
18 
189 
4,245,696 
5/20/1919 
20 
191 
4,290,624 
5/20/1919 
11 
210 
4,717,440 
5/22/1919 
14 
69 
1,550,016 
5/23/1919 
16 
213 
4,384,832 
5/24/1919 
17 
391 
8,783,424 
5/24/1919 
These estimates are based 
the average samples. 
on 15-minute catches and 
represent a few of 
The following ten samples of soil from Ditch No. 1 were 
taken in late October. The samples were from the bottom 
and sides, and each contained 36 cubic inches of soil. 
TABLE IV. — SEEDS IN MUD OF DITCH 
Sample No. 1 
Species of weeds — No. of seeds 
Iva xanthifolia 1 
Polyg-onum persicaria 1 
Amaranthus blitoides 2 
Amaranthus retroflexus 3 
Chenopodium album 1 
Sample No. 2 
Amaranthus retroflexus 2 
Chenopodium alburn 2 
Polygonum persicaria 1 
Rumex crispus 1 
Sample No. 3 
Amaranthus blitoides ... 
Amaranthus retroflexus . 
Chenopodium album 
Echinochloa crus-galli . . 
Polygonum aviculare . . . . 
Polygonum convolvulus . 
Rumex crispus 
Sample No. 4 
Amaranthus blitoides ... 
Chenopodium album 
Polygonum convolvulus . 
Sample No. 5 
Amaranthus blitoides ... 
Amaranthus retroflexus . 
Carex sp 
Chenopodium album 
Polygonum aviculare ... 
Polygonum persicaria . . . 
Tragopogon sp 
Sample No. « 
Amaranthus blitoides . . . 
Amaranthus retroflexus , 
D 
4 
5 
4 
4 
2 
9 
2 
1 
1 
1 
4 
6 
1 
1 
2 
3 
Species of weeds — No. of seeds 
Iva xanthifolia 35 
Polygonum aviculare 2 
Rumex crispus 2 
Taraxacum officinale 1 
Sample No. 7 
Amaranthus blitoides 5 
Amaranthus retroflexus 6 
Polygonum convolvulus 4 
Polygonum aviculare 2 
Carex sp 1 
Chenopodium album 4 
Portulaca oleracea 1 
Sample No. S 
Polygonum convolvulus 2 
Polygonum aviculare 1 
Carex sp I 
Chenopodium album 3 
Portulaca oleracea 3 
Amaranthus blitoides 4 
Amaranthus retroflexus 10 
Sample No. J) 
Rumex crispus 19 
Chenopodium album 3 
Amar-anlhus blitoides 2 
Polygonum convolvulus 4 
Melilotus alba 3 
Iva xanthifolia 1 
Sample No. 10 
Rumex crispus 19 
Hordeum jubatum fi3 
Amaranthus blitoides 2 
Amaranthus retroflexus 1 
Melilotus alba 1 
Polygonum convolvulus 1 
