IOWA ACADEMY OF SCIENCE 
25 
Name of Seed 
Years 
Old 
No. of 
Seeds 
Percent- 
age of 
Germina- 
tion 
Malvaceae — 
Abutilon avicennse 
57 
45 
6 
Var. Bebriana 
Hibiscus trionum 
57 
12 
Gossypium herbaceum 
10 
80 
Leguminosae — 
Acacia diffusa 
57 
32 
9 
Acacia penninervis 
57 
15 
13.3 
Cytisus albus 
51 
54 
78 
Melilotus alba 
44 
250 
52 
Melilotus alba 
77 
1000 
18.2 
NympTiaeaceae — 
Nelumbium luteum 
55 
6 
63 
Rhamnaceae — 
Ceanothus Americanus 
15 
20 
0 
Crueiferae — 
Brassica alba 
77 
115 
0 
Compositae — 
Cicborium intybus 
10 
100 
50 
Helianthus annuus 
15 
20 
0 
Gramineae — 
Triticum vulgare 
10 
100 
7.5 
Zea Mays 
7 
100 
36 
Bromus mollis 
10 
250 
0 
THE PROLONGED VITxVLITY OP SEEDS. 
The explanation of this must be sought not only in the structure of 
the seed coat but in the amount of respiration that is carried on at least 
at times and depends on external conditions and lastly upon certain herit- 
able qualities. One is perhaps not very far wrong in concluding with 
Kolkwitz^^ that respiration is not essential to continue the vitality of 
seeds since many seeds will not lose their vitality by prolonged heating. 
Thus Pouchet"^ states that the vitality of the seeds of Medicago sativa 
was not destroyed when heated with steam heat for four hours; and 
HaberlandP^ found that a large number of seeds of sixty-four different 
species did not lose their vitality after having been heated to 100 degrees 
C. for forty-eight hours. Among these we may mention some of the 
seeds of Gramineae, Leguminoseae, Cucurhitaceae, etc. Such seeds usu- 
^^Berichte d. Bot. Gesell. 19:285. 
^^Compt rend. 63:939. 
^^Allgem. Land. -u. forstw. Zeit. 1:389. 
Utersuchungen auf dem Gebiete des Pflanzenbaues. 2:79. 
