1906| CROCKER—DELAYVED GERMINATION 279 
TABLE VU. 
X. canadense; UPPER SEEDS. 
PER CENT. GERMINATED AFTER 
SEEDS Coats | TEMP | 
| 3 days 6 days 33 days 
Aires pint Pathered oc. nie iv cig os: on | 28-33 ° > 3 
1904 stored in laboratory 1 yr....... on | 28-33 9° S es 
1904 in lab. 4 mos., buried 8 mos.... on | 28-33 44 96 
POOR TUSL patncred oi oe ae off 18-22 48 100 100 
1904 stored in lab. 1 yr.:.......... off | 18-22 20 42 100 
1904 in lab. 4 mos., buried 8 mos. | off | 18-22 Oo] 4 94 
in the laboratory less prompt germination, in upper seeds of 1904 
buried eight months much less prompt germination. From this 
table two things are evident. A period in the ground causes a partial 
disintegration of the seed coats which lowers the germinative mini- 
mum temperature with the seed coats intact. This accounts for the 
results in Table VII with the temperature at 28-33° and the coats 
intact. The vitality (if we mean by vitality the readiness with which 
seeds will germinate at a given temperature) of the embryos falls 
somewhat with a year of dry storage and markedly with eight months 
in the ground. 
2. AXYRIS AMARANTHOIDES. 
L. R. Watpron of the North Dakota Agricultural College informed 
me that Axyris amaranthoides bears two kinds of seeds. One grows 
soon after being subjected to germinative conditions and the other 
fails to grow under similar conditions. The former, which is flattened 
and winged (fig. 4, a) he designated as a; the latter, which is almost 
spherical (fig. 4, b), as 6, From material 
kindly furnished by him I have found that 
the distal portions of the branches bear 
entirely form a, and the proximal portions 
entirely form 6; while the intermediate zone 
bears both forms even within the same seed 
oh fos! es is either one form or the 5, —Dim eae 
g no intergrading. Seeds seeds of Axyris amaran- 
of form a and 6 are about equal in number. “24s. = 
It is found that form 0 fails to grow because the seed coat is only 
very slowly permeable to water, Form a soaked in water at 2 tek 
