Beer, Development of the pollen grain and anther of some Onagraceae. 297 
Pollen grain 
n 
68 
36 
30 
70 
36 
32 
70 
40 
II. The stamens from another bucl were examined in 
1. 0,75 % Na CI. 
= 62 fi . 68 y, 1 )' 
cavity = 36 y 
„ protoplast = 24 y 
2. Egg-white. 
Pollen grain — 62 y 
„ cavity = 36 y 
„ protoplast = 26 y 
3. Strong Elemmings solution. 
Pollen grain = 64 y 
„ cavity ~== 38 y 
„ protoplast = 26 y . 30 
4. Merkels solution. 
Pollen grain = 66 y, 
„ cavity = 40 ^ 
„ protoplast = 40 
This caused the protoplast to swell up. 
5. Strong chrom-acetic solution. 
Pollen grain = 66 
„ cavity = 36 
„ protoplast = 28 p. 
III. Stamens from another bud examined in 
1. 0,75% Na CI. 
Pollen grain = 80 y, 
u, 
u. 
u, 
u, 
u. 
a, 
u, 
u. 
n 
cavity = 46 u 
ri 
n 
protoplast = 32 y. 
2. Examined in a drop of juice squeezed from the stem 
of Oenothera longiflora. 
Pollen grain = 76 y . 76 y,. 80 y, 
„ cavity = 42 y . 44 y . 46 y, 
„ protoplast = 32 y . 36 y . 34 y. 
3. In 5% cane-sugar solution. 
Pollen grain = 72 y. 
„ cavity = 42 y, 
„ protoplast == 30 y. 
IV. In another bud pollen examined in a drop squeezed from 
stem of Oenothera longifiora. 
Pollen grain = 72 y, 
„ , cavity - 42 y, 
„ protoplast = 34 y. 
V. In another bud pollen was examined in 
1.0,6% Na CI. 
Pollen grain 
cavity 
protoplast = 28 y. 
n 
ii 
62 p, 
34 ■//, 
1 ) Tlie successive nmnbers (62 /u and 68 /u in this case) denote measnre- 
ments of several pollen grains. Eacli vertical series of figures corresponds 
to one pollen grain. 
