Tg06] CROCKER—DELAYED GERMINATION 283 
Nosse and HANLEIN show the germination of only 0.25 per cent. 
of P, major, 10.75 per cent. of P. media, and 21.75 per cent. of 
Thlaspi arvense after 1,173 days. In the last species the germination 
is late in that period. 
From Table VIII several important facts are evident. The tem- 
perature of 18-22° is below the minimum germinative temperature 
of seeds of P. major with seed coats intact or broken, and below that 
of P. Rugelii and Thlaspi arvense with seed coats intact. It is very 
near the germination minimum of P. Rugelii with seed coats broken 
and well above that of Thlaspi arvense in similar condition. A very 
marked increase in germination is secured by rupturing the coats 
even when the most favorable temperatures are used, High tem- 
peratures, then, will overcome only in part the seed coat effects. 
High temperatures are more efficient in overcoming the seed coat 
effects in P. major than in P. Rugelii. 
In Table IX a similar effect of rupturing the seed coat is shown 
for Capsella Bursa- pastoris, Lysimachia vulgaris, and Euphorbia 
Cyparissias, It should be mentioned that the region and extent 
TABLE: IX. 
TEMP. 18—-22° EXCEPT FOR IRIS, WHICH WAS 28-33°. 
PER CENT. GERMINATED AFTER 
SPECIES Coats 
1 day | 3 days| 6 days | 14 days | 20 days | 30 days 
Abutilon Aviceniae. 33. G3], entire ° 13 13 13 13 13 
broken 48 98 98 98 98 98 
mvend ths 66 ee entire © ° 8 8 8 8 
broken ° 4 92 96 96 96 
Capsella Bursa-pastoris...... entire fe) 8 14 15 15 AD 
Ch ; broken fo) 80 oo 100 100 100 
e enopodium album........ .| entire ° Io 16 16 16 16 
: broken ° 80 100 100 100 100 
Euphorbia Cyparissias ....... entire ° ° 2 20 20 20 
* : broken fa) 20 84 84 84 84 
Lysimachia Wilgatie. (20 entire ° ° ° ° ° ° 
: broken ° 44 64 64 64 
Axyris amaranthoides A...... entire ° 76 92 94 96 96 
: broken 14 100 100 100 100 100 
A. amaranthoides B......__. entire ° ° ° ° ° ° 
si ae roken Be OO 4 TOG £00 < |) 100%") 00 
Tris ec cap on ° ° ° fs) ° ) 
- cap off ° 6 18 98 8 
Tris Pseudacorus.,......-... a on ° ° & ° a 
cap off ° 14 4. 32 et 4 OF. 1-97 
Ce retest aus 
