MATROCLINIC INHERITANCE 
change by virtue of which all individuals of the line became mutable. 
The phenomena are not quite comparable in the case of mass-mutant 
Oe. Reynoldsii, and lead one to wonder if the change in the genetic 
physiology of the original individual of mass-mutant Oe. Reynoldsii 
may not have been a premutation accidentally detected at the actual 
time of origin. Speculation on such a point, however, will hardly be 
worth while until the investigations shall have been pushed much 
further than they have been as yet. 
To those who may desire to explain the mutations of Oe. Reynoldsii 
on a Mendelian basis the facts are very refractory. The lines have 
been grown from guarded seeds since 191 1, and have probably been 
self-pollinated much longer, for the species is one of the smaller-flowered 
self-pollinating types, producing abundant pollen that is liberated on 
the receptive stigma a day, or even two days, before the flowers open. 
If the wild parent plant had been an Fi hybrid, or a heterozygote of a 
later generation, the first generation in the garden should have vshown 
segregation, whereas the first polymorphic progeny was obtained two 
generations later. An explanation based on the multiple factor hy- 
pothesis is blocked by the fact that the mutations do not act as Men- 
delian recessives, but show strict matroclinic inheritance when crossed 
with the parent type. 
Seed Sterility of the Mass-Mutant Individuals 
Returning to the problem presented by the two types of individuals 
of f. typica, we see from Table I that there is at least one character 
by which they may be distinguished. All those plants giving rise to 
uniform progenies have reasonably good seeds, relatively many of 
which (58 to 84 percent) readily germinate. Those giving rise to 
polymorphic progenies, on the contrary, have very poor seeds, few 
of which (2 to 5 percent) are capable of germinating. 
When the seeds for two of the polymorphic progenies (Nos. lib 
and 12 in Table I) were counted off it was found that only about 5 
percent of the seed-like structures Were actually perfect seeds with a 
good embryo. The remainder were either empty shells, or else con- 
tained a small amount of yellowish disintegrated tissue. Many were 
examined. It is therefore certain that the low germinability of the 
seeds that yield polyinorphic cultures is not to be attributed to delayed 
germination. If a cytological study now in progress throws any 
light on the reason for the seed sterility, we may be well on the way 
