169 



In Cladrastis the seeds were classified not merely according to 

 the number produced in the pod, but according to their position 

 in the pod, the positions being numbered from the proximal to 

 the distal end. Table VI. gives the results. When only one 

 seed is produced the mean weight is higher than when the pod 

 contains two or more. There is no essential difference between 

 2- and 3-seeded pods. Within a pod containing 2-4 seeds the 

 mean weight decreases from the proximal towards the distal 

 position. 



Table VI 



Seeds per 





Pos 



ition of Seed in Pod 





Pod 















I 



2 



3 



4 



All 



I 



(iV=500) 

 ■03385 









(.¥=500) 

 ■03385 



2 



(AT =500) 



(AT =500) 







(A^ = iooo) 





.03267 



-03134 







.03201 



3 



{N = ioo) 



(iV=ioo) 



(AT = 100) 





(A^=300) 





■03257 



■03183 . 



.03163 





.03201 



4 



(iV=22) 



{N=22) 



{N=22) 



(AT =22) 



(AT =88) 





.03209 



.03086 



■03013 



■02945 



.03064 



The weights could not be determined for the seeds individually 

 to allow of obtaining the probable errors which are much needed 

 where differences so slight as those given here are involved. 

 They were weighed in groups of 25, and when these individual 

 samples from different kinds of pods or positions are compared, 

 the results emphasize the general trustworthiness of the con- 

 clusions drawn above. 



The exact degree of interdependence between number of seeds 

 per pod or position of the seed in the pod and seed weight cannot 

 be determined from this series of data since the variability in 

 seed weight is unknown.* It is evident, however, that in the 

 absolute size of seed only very slight (although definite) dif- 

 ferences are referable to characteristics of the pod. I think that 

 a priori physiologists would have expected greater differences. 



Cold Spring Harbor, L. I., 

 July 14, 1911. 



* Data for another species in which this point has been determined are now in 

 hand. 



