1913] Bartlett,— Sex Forms in Plantago lanceolata 177 
greater tendency to produce 2d form plants in the megaspores of Nos. 
9, 12 and 20 than in the megaspores of their mother. The pollen 
parents of the first F; were of course unknown, but if it is safe to argue 
from the frequency of the sex forms of Plantago lanceolata in nature 
they were probably whites belonging to a non-gynodioecious strain. 
Would pollen from a pure 1st form strain be likely to have less ten- 
dency to produce whites than pollen from a strain consisting of two 
forms? — But in view of the small number of plants in the F; cultures 
and the relatively large number of unclassified plants which they 
contained, it is hardly profitable to speculate on their unexpected 
divergence. 
As a whole, the table shows beyond doubt that in the physiologically 
gynodioecious strain of Plantago lanceolata which the writer has culti- 
vated there are 1st and 2d form hermaphrodites in practically equal 
numbers in the progeny of both 1st and 2d form mothers. The mode 
of inheritance of the 2d form hermaphrodite in the physiologically 
gynodioecious strain is probably the same as that of the purely 
pistillate form in the structurally gynodioecious strains which have 
been studied by Correns.! This investigator has shown by pollinating 
the same mother plant with pollen from different plants, and, con- 
versely, by pollinating different mother plants with pollen from the 
same plant, that both the seed parent and the pollen parent influence 
the proportion of sex forms in the progeny. The inheritance of the 
sex forms is not wholly determined by either parent. It should, 
therefore, throw some light on the mode of inheritance of the sex 
forms if a 2d form hermaphrodite were pollinated by a 1st form her- 
maphrodite belonging to a strain not only functionally but also 
structurally pistillate and, conversely, if a structurally pure pistillate 
plant were pollinated by a 1st form hermaphrodite belonging to the 
physiologically gynodioecious strain. Such crosses might result in a 
progeny in which one could distinguish by their morphological charac- 
ters between those pistillate plants which had inherited the pistillate 
tendency through the pollen parent and those which had inherited it 
through the seed parent. In this connection attention may again be 
called to the one aberrant structurally pistillate plant (No. 7) which oc- 
curred in the first (open-pollinated) F; generation. Of 451 functionally 
1 Correns, C.: Die Rolle der mánnlichen Keimzellen bei der Geschlechtsbestim- 
mung der gynodioecischen Pflanzen. Ber. d. deutch. bot. Ges. xxvia, pp. 686-701. 
1908. 
