50 University of California Publications in Agricultural Sciences [Vol. 2 



As for the second hypothesis, that the new variety originated 

 from teratoloo'ical flowers of J. calif ornica, this seemed very 

 unlikely after testing sixty-eight abnormal nuts from several 

 different trees and failing to secure it. and especiall}^ after dis- 

 covering that the new form does originate from nuts of normal 

 appearance. At the same time, the occurrence of teratological 

 leaves, flow^ers, and fruits in this species would certainly indicate 

 an unstable condition, which finds its most frequent expression 

 in these abnormal features of the somatoplasm and which may 

 occasionally result in such segregations in certain cell divisions 

 preceding or accompanying gametogenesis as would result in 

 what we call mutation. As a matter of fact the tree of J . cali- 

 f ornica, mentioned above, which has been under observation about 

 two years (tree no. 16 mentioned at the close of the preceding 

 paper), produced in 1913 a few clusters of these abnormal late 

 nuts. These were found while gathering the normal nuts from 

 this tree. Each cluster (produced on a single catkin) was gath- 

 ered separately and given a number. A tree label bearing the 

 same number was attached to the twig that bore that particular 

 cluster. From each of three of these clusters of teratological 

 fruits two or more quercina seedlings have appeared. Plate 15, 

 figure 3, shows the seedlings grown from abnormal cluster number 

 B4 which was borne on a late-appearing catkin which sprang 

 from the base of a normal pistillate catkin on twig number 151. 

 In this case there are four typical calif ornica plants {a, b, c, d), 

 four quercina plants (e, /', g, //), and two seeds that did not 

 germinate. It may be questioned whether seedling Ji could be 

 properly classified at such an early stage. Sufifice it to say that, 

 even at the time when the stem is just pushing through the soil, 

 the appearance of quercina is quite distinct from that of cali- 

 f ornica. Seen from above the former has the shape of a rosette 

 while the latter appears as a cone. This is due to the decided 

 difference in the apices of the leaves (cf. b and e). Seedling h 

 presents a fine exhibition of geotropism due to the position in 

 which the seed happened to be planted. The extreme abnormality 

 of some of the nuts of this cluster is strikingly shcnvn in a, c, e 

 and f. In each of these seeds one cotyledon was confined within 

 a sector ecjual to about one-third the volume of the nut. It is 



