JOURNAL OF AGRICULTURAL. RLSEMCII 
DEPARTMENT OF AGRICULTURE 
Vol. V Washington, D. C., December 6, 1915 No. 10 
INHERITANCE OF LENGTH OF POD IN CERTAIN 
CROSSES 
By John Belling , 1 
Assistant Botanist , Fbrida Agricultural Experiment Station 
INTRODUCTION 
The inheritance of a difference between two plants has sometimes, 
though not often, been studied both qualitatively and quantitatively. 
Correns (5) 3 has shown that this can be done even with differences in 
flower color. The inheritance of a large-size difference can occasionally 
be followed by mere inspection, as in crosses of some tall and dwarf 
races of peas (Pisum sativum) (13); sweet-peas (Lathyrus odoratus) 
(1, p. 280-281); beans (Phaseolus vulgaris) (8); and maize (Zea mays) 
( IO )- 
Even with accurate measurements, however, it will probably not be 
possible to keep track of a single small-size difference, for its segregation 
may be masked by the modifications. But if several small genetic 
differences affect the size of the same plant organ, it would usually be 
still less possible to disentangle the segregation in the second generation 
of a cross, as Johannsen (12) has proved. The masking effect of the 
modifications may, however, be lessened by choosing those plant organs 
which are least liable to modification and which are also repeated many 
times on each plant, such as flowers (6) or pods with the modal number 
of consecutive ripe seeds (2). In one such case some of the members 
of a fraternity were grown on poles 8 feet apart, and others were sown 
at intervals of 4 feet in a thick row of sorghum. Though the crops of 
the stunted plants averaged only one-twentieth of those of the others, 
yet the average length of their 5-seeded pods reached 94 per cent of that 
of the pods of the well-nourished plants. 
In the reciprocal crosses described in this paper, the length of pod was 
first studied qualitatively and then quantitatively. All the families 
1 1 express my thanks to Messrs. C. D. Gunn and C. W. Long, of the Florida Experiment Station, for 
their careful work in measuring pods. 
2 Reference is made by number to “Literature cited," pp. 419-420. 
Journal of Agricultural Research, Vol. V, No. 10 
Dept, of Agriculture, Washington, D. C Bee. 6, 1915 
Fla.—1 
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(40s) 
