536 
GENETICS: E. B. BABCOCK 
it must be a hybrid. To this objection I can only reply that thus far 
I have been unable to discover any morphological evidence that Garden 
Grove No. 16 is a hybrid. 
In 1913 I gathered about 350 clusters of nuts from this tree and grew 
each lot separately. Among them were several clusters of teratological 
nuts. A single quercina seedling appeared in each of 42 of the normal 
clusters while three of the teratological clusters produced two or more 
quercina seedlings in each cluster. These results indicate that, while 
teratology per se is not the cause of the mutation, yet in a tree capable 
of producing quercina seedlings the mutation occurs more frequently 
among teratological than among normal flowers. The fact that in all 
the normal clusters producing quercina seedlings only one mutant came 
from each cluster, at once raised the question as to whether a certain 
location of the flower in the pistillate catkin might be associated with 
the occurrence of the mutation. This question is not yet fully answered 
but it is known that at least two different locations in the catkin are 
associated with the mutation and hence it can be stated definitely that 
no certain location of the pistillate flower is exclusively associated with 
the occurrence of the mutation. 
On account of the interesting differences in chromosome numbers 
found among some of the evening primroses, we have determined the 
number in the somatic cells of both types of seedlings produced by 
Garden Grove No. 16. By planting one seed in a small pot excellent 
root-tips for cytological study are thrust out through the hole in the pot. 
The chromosomes are very small and cells that show • satisfactory 
figures for counting chromosomes are comparatively rare. However, 
I am satisfied that the number of chromosomes in both types of seedlings 
is thirty-four. If further study reveals the same number of chromosomes 
in both quercina and californica seedlings secured from other sources, 
we must conclude that the mutation producing quercina is not due to 
a change in the number of chromosomes. The chromosome numbers 
for hindsii and its quercina mutants have not yet been determined. 
Meanwhile, efforts have been made to test the genetic relation of 
quercina to californica by crossing. I have eight Fi trees of the cross 
/. californica 9 X J- californica mut. quercina d^, all of which resemble 
J. californica. They produced some open pollinated nuts in 1914 and 
among the progeny of one of these eight (08 HiFiPSc) there has appeared 
one quercina seedling. This indicates that at least one of the eight is a 
veritable hybrid and not a parthenogen as might be the case judging 
from the results of certain crosses with oak pollen also made in 1908. 
Hence it is possible that the ratios produced in future tests of this indi- 
