530 
IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 
As might be expected, the legumes stand at the head of the 
list. The oil-bearing seeds, also, contain considerable amounts of 
protein. On the other hand, those that contain notable quantities 
of starch, as the Polygonaceac, are much lower in protein. Those 
at- the end of the list represent seeds with a thick woody coat 
.sufficient in amount to reduce greatly the protein percentage. 
On the whole, there is rather a close agreement in composition 
between related species of the same genus. The list, however, is 
as yet too incomplete to warrant discussion in greater detail. 
In the paper on the anatomy of the Leguminosae attention is 
called to the presence of fat when the carbohydrates are wanting. 
In such cases fat is present usually in greater amounts than where 
the starch occurs. The reserve food not only varies in the tribes 
but in related genera. In the Yiciese and Phaseolese the reserve 
food consists largely of carbohydrates in the form of starch 
and proteins, the latter in the form of aleurone grains. In the 
Caesalpinieac e. g., honey locust, the reserve food occurs in the 
form of proteins and fat. In the soy bean (Soja hispida) it 
occurs largely as fat and proteins, in clover as starch, protein 
and fat. 
The microchemical tests recorded in this paper consisted of 
the usual test for starch, namely, iodine in potassium iodide, 
iodine for protein, Sudan III for fat, ferric chloride for tannin. 
Many of the testa or pericarps have some tannin. Tannin was 
not, however, found in the endosperm of many seeds and for this 
reason the test is omitted from the table. The pericarps of many 
seeds, as well as the testa, contain some tannic acid, although the 
amount with some exceptions is very small. Most of the tests 
given in the table were made by us. Where the tests were made 
by others, they have been starred. Most of the starred tests were 
taken from Harz, Winton and Moeller. 
MICHROCHEMICAL TESTS FOR STARCH, PROTEIN AND FAT. 
Name 
Starch 
Protein 
Fat 
Graminese 
Agropyron repens _ 
abundant 
some 
little 
Aristida ramosissima - 
compound 
grain abundant 
some 
little 
Bromus ciliatus var. purgans 
simple 
abundant 
some 
little 
*Bromus secalinus 
simple grains 
some 
little 
Digitaria humifusa _ 
abundant small 
polygonal simple 
some 
little 
