622 
ZOOLOGY: S. O. MAST 
the proximal and middle row of phalanges. One or more, often all of 
the fingers are involved. The resulting deformity is known in the 
community as 'stiff fingers,' in contradistinction to the normal which 
are called 'crooked fingers.' This condition has been transmitted 
through seven generations, the progenitor of the family having migrated 
from Scotland to Virginia in 1700. There are connections of the family 
still in Scotland who carry the trait. 
In the Virginia branch, which has been made the object of this statis- 
tical study, record has been secured of 312 descendants, among whom 
there were 84 affected persons, a few more than the 25% of the total num- 
ber which would be expected. Excluding the incomplete families of 
the first three generations, in which were recorded few other than the 
affected persons carrying the trait, there are 72 completed families com- 
prising 302 individuals. Of these 72 completed families, 44 of them 
were from the mating of unaffected parents with 152 unaffected chil- 
dren. Of the 28 families in which there was an affected parent, there 
were 150 children, 78 of them, or 52%, carrying the trait. It has been 
observed that the trait may be transmitted in outspoken form by a 
parent in whom it is inconspicuous, though never by an unaffected 
parent. The trait moreover is transmissible by either sex, and both 
hands and feet of the affected individuals may be involved. 
The character, in short, behaves as a simple Mendelian dominant, 
with equal chance, among the offspring of affected individuals, that it 
will be or will not be inherited. 
This paper will appear in full with photographs and charts in a forth- 
coming number of Genetics. 
THE RELATIVE STIMULATING EFFICIENCY OF SPECTRAL 
COLORS FOR THE LOWER ORGANISMS 
By S. O. Mast 
ZOOLOGICAL LABORATORY. JOHNS HOPKINS UNIVERSITY 
Presented to the Academy. November 10. 1915 
The relation between color and reactions in organisms has for many 
years been a prominent problem in the study of behavior. The earlier 
investigators (Bert, Lubbock, Romanes, Graber and others) were inter- 
ested in this problem largely from the point of view of comparative 
psychology. Their aim was to ascertain the relation between color- 
vision in man and in the various animals with the hope of thus eluci- 
dating the evolution of psychic phenomena. 
Loeb studied the reaction to colors in plants and in animals for the 
