2 BULLETIN 1197, U. S. DEPARTMENT OF AGRICULTURE. 
the rachis is fragile and breaks up during the threshing operation, 
leaving most of the spikelets whole. The segments of the rachis re- 
main attached to the spikelets. 
The kernels of emmer and spelt are somewhat similar. They are 
long,, slender, and tapering (Pis. I and II) . The kernels have a wide, 
shallow crease, angular flat cheeks, and a long pointed brush. The 
kernels of spelt are somewhat more flattened, have a wider, more open 
crease, and are somewhat less humped than the kernels of emmer. 
The kernels of both emmer and spelt are red in color and usually are 
semihard or hard in texture, the kernels of emmer usually being the 
harder of the two. The kernels of einkorn are also reddish in color 7 
but are smaller than the kernels of spelt and emmer and are com- 
pressed laterally. 
Recent studies indicate that einkorn, emmer, and spelt differ in the 
number of chromosomes. Sakamura (36) 1 states that einkorn has 14 
chromosomes in the somatic cells, emmer 28, and spelt 42. He fur- 
ther states that T. turgidum, T. durum, and T. polonicum have the 
same chromosome number as emmer, and T. vulgare and T. compac- 
tum have the same number as spelt. Sax (4%) has found the same 
chromosome numbers as reported by Sakamura. Kihara (22) reports 
that F x hybrids between members of the spelt and emmer groups con- 
tain 35 chromosomes in the somatic cells. Individuals of the F 2 gen- 
eration varied from 31 to 42, while those of the F 3 generation varied 
from 28 to 41 in chromosome numbers. 
Schulz (44) concludes, from a consideration of the botanical char- 
acters of the wheats, that einkorn, emmer, and spelt have had their 
origin from different wild species, and he classifies the wild and culti- 
vated wheats into three lines or groups, according to supposed lines 
of descent. 
Vavilov (65) divided the species of wheat into three groups on the 
basis of their reaction toward leaf rust, Puccinia triticina Eriks., and 
mildew, ErysipTie graminis DC. Einkorn, emmer, and spelt were 
in these separate groups, although there were some exceptions, both 
susceptible and immune strains of emmer being found. 
Zade (70) likewise divides the wheats into three groups on the basis 
of his serological studies, einkorn, emmer, and spelt being again in the 
separate groups. 
It is apparent from the various studies that have been made that 
einkorn, emmer, and spelt belong to what may be considered as dif- 
ferent species of wheat. There is a further difference in the adapta- 
tion between the emmers and spelts grown in the United States. 
Spelt is better adapted to humid regions, being comparable to soft 
red winter wheat in this respect, and emmer is better adapted to 
regions of lower rainfall, being comparable to durum and hard red 
winter wheat. 
CHARACTERISTICS OF EMMER. 
E mm er usually has pithy culms and pubescent leaves. The spikes 
are very dense and laterally compressed, being narrow when viewed 
from the face of the spikelet and wide from the edge view (PL I). 
The pedicel (joint of rachis) is short, narrow, and pointed and usually 
remains attached to the spikelet which it bears. The spikelets are 
flattened on the inner side. They usually contain two (or sometimes 
1 Serial numbers (italic) in parentheses refer' to "Literature cited," at the end of this bulletin. 
