10 Rhodora [JANUARY 
able everyone of extended experience knows too well, and it sometimes 
seems as if De Vries could nowhere have found a better subject for the 
study of mutations. 
In fact, less than two years prior to the publication of Forsaith’s 
paper, Jeffrey made the following seemingly authoritative statement: 
“all the pollen grains of Epilobium (Chamaenerion) angustifolium are 
perfectly developed. I have examined the pollen of the species under 
discussion from widely separate geographical regions and under differ- 
ent conditions of growth and season, with the uniform result, that the 
pollen is perfect and invariable in any important respect. ŒE. angusti- 
folium is a species which apparently is not known to hybridize with 
other species and indeed it is not easy to see how it could cross with 
those having their pollen grains in tetrads. The perfection of the 
pollen in view of this condition appears particularly significant. The 
failure of E. angustifolium to hybridize in nature with other species of 
the genus is doubtless due to the fact that it is morphologically very 
distinct from these and would in all probability produce, if artificially 
crossed, only sterile hybrids.” ! Somewhat earlier, likewise, Jeffrey 
had asserted with positiveness that the pollen of E. angustifolium is 
perfect, saying in his paper, The Mutation Myth, “In all the abundant 
material of the species examined the pollen was entirely normal.” ? 
In less than two years, then, as indicated by Forsaith’s publication 
from Professor Jeffrey’s laboratory, Epilobium angustifolium, with the 
abruptness of a De Vriesian mutation, changed from a species in which 
“the pollen is perfect and invariable in any important respect” to 
one in which, in the northern United States and southern Canada, 
England, Japan, and elsewhere outside the range of any other species 
with simple pollen grains, the pollen is said to be frequently imperfect. 
That imperfection of pollen in this species cannot be asserted to be due 
to hybridization with Æ. latifolium should be apparent from the vast 
distances (often 100 to 1000 miles and sometimes overseas) between 
the supposed hybrid offspring and the nearest colonies of one of the 
assumed parents. 
Gray HERBARIUM. 
1 Jeffrey, Am. Nat. xlix. 11 (1915). 
2 Jeffrey, Science, n. s. xxxix. 490 (April, 1914). 
