344 BOTANICAL GAZETTE [NOVEMBER 
some normal plants, two mutant hybrids, and will give the constitu- 
tion of their progeny, together with that of two normal individuals 
of O. gigas, in table V. The numbers of seedlings have been very 
small in this case, owing to the small degree of fertility of the pollen 
of O. gigas nanella. 
“TABLE V 
DWARFS IN THE FIRST GENERATION OF O. gigas XO. gigas nanella 
Number of Number of Percentage of 
seed-bearer seedlings Dwarfs dwaris 
Paar er es 38 II 30 
Ses re 65 28 43 
rape ea rageeeiss ak 28 I L S 
Pie Se ee 50 2 } 
The first two seed-bearers had evidently about one-half of their 
egg cells mutated into nanella, which by the fertilization with the 
pollen of dwarfs must, all of them, become nanella specimens. The 
two last-named plants, although externally not differing from the 
others, had only very few mutated sexual cells, and therefore pro- 
duced only about 3 per cent of dwarfs. 
TABLE VI 
DWARFS IN THE SECOND GENERATION OF O. gigasXO. gigas MUT. nanella 
Seed-bearer j — Dwarfs ae om -e - 
Ayo: gigas nanella XO. gigas 
om eee ana ra oir prea mrMn ee Oe 291 45 15 
UNV Pee NUE eRe ee eek 6 12 17 
B, OQ. gigs XO. gigas nanella 
ING Bee. Pc ce eek by he epee ees 60 16 27 
No. ; Ce ee eens Chee eas 310 73 24 
ING So ee ig ia eee 304 62 20 
ING Bee ee 74 14 19 
I Be ee in ee eee 283 46 16 
apg he ee ee 210 30 14 
C. O. gigas mut. hybrid<O. gigas nanella 326 52 > 
The experiment showed at the same time that hybrids between 
O. gigas and O. gigas nanella have the features and the stature of the 
former type, and thereby justified the assumption made above in 
the explanation of the behavior of mutant hybrids. 
I made the reciprocal cross in the same year, fertilizing some 
dwarts of my race by the pollen of normal plants of O. gigas. The 
