Voh.7, 1921 
PHYSICS: A. F. BLAKESLEE 
117 
Naudin 1 reports in an Fi between an inermis variety (D. laevis) of 
D. Stramonium and the armed type, that while most of the plants had 
spiny fruits, others had fruits with reduced spines. Many of the capsules 
on three out of the forty plants in this generation were very spiny on part 
of the surface while totally smooth on the rest. Naudin believed that they 
united thus by distinct and separate compartments the distinctive traits 
of the parental types D. laevis and D. Stramonium. He calls this ll hy- 
bridite disjointe" and cites in this connection the condition in the graft 
chimera Cytisus Adami. In a series of F 2 plants from the same original cross 
Naudin found 6 individuals out of 38 which again showed more or less 
well marked his "kybridite disjointed and which were presumably 
Quercinas. 
Godron 2 reports finding capsules partly spiny and partly smooth. He 
objects, however, to Naudin's interpretation that the separation of the 
fruit into smooth and spiny portions is due to their origin from smooth and 
spiny parents, since he says that he has found this condition when both 
parents had spines. 
Bateson and Saunders, 3 after discussing the intermediate color of the 
flowers in the Fi between white and purple flowered forms, say: "The 
occurrence of intermediate forms was also occasionally noticeable in the 
fruits. Among the large number of capsules examined, there were some 
of the mosaic type, in which part of the capsule was prickly and the re- 
mainder smooth, while others suggesting a blend, were more or less prickly 
all over, but the prickles were much reduced in size, and often formed 
mere tubercles. These mosaics occurred as rare ties both on prickly in- 
dividuals and on smooth ones still more rarely." Further evidence point- 
ing to the Quercina nature of these abnormal capsules is given in their 
following statement: "Such intermediate fruits were most often found 
towards the end of the flowering season." 
It may be stated that the writer has grown many thousand plants of 
the Jimson Weed, including large numbers of individuals that were hetero- 
zygous for inermis capsules, but has never observed any except Quercinas 
which showed a mosaic arrangement of the spines on the fruits, with some 
valves smooth and others more or less spiny. Despite their misconception 
of the nature of the phenomenon which they observed, it is highly prob- 
able that the investigators mentioned were describing the same type of 
plant that we have considered under the term Quercina. 
The Quercina character does not breed true. It is transmitted by seed 
to about 79 per cent of its offspring when pollinated from normal plants. 
The remaining 21 per cent normal offspring do not produce Quercina 
seedlings in the next generation, and hence do not carry the character in 
a recessive condition. 
