370 BOTANICAL GAZETTE [NOVEMBER 
ment of the flower axis allows for the repetition of an indefinite 
series of immature bulbs, formed from runners or in situ, but 
introducing no new structures during the whole period of immature 
development. With the formation of the flowering shoot, the 
vegetative structures become secondary in importance, and the 
renewal bulb is developed from an axillary bud at the base of the 
shoot. The continuation of the individual is thereafter without 
vegetative multiplication normally, the increase being secured by 
the seeds. 
The geographical distribution of species and their relation to each 
other in structural details indicate that the genus originated in 
that region of the Pacific coast now included in the state of Oregon, 
and has been distributed along lines approximately following the 
present habitats of the several species. In the progress of migra- 
tion the advancing species developed special methods for rapid 
descent into the soil, which in some forms has become a means of 
numerical increase. 
In the development of means of vegetative multiplication, 
elongation of the structure immediately about the stem apex (In 
the seedling the base of the cotyledon, in the western forms the base 
of the petiole) was followed by the elongation of the scales of 
axillary buds, thus forming additional descending axes, each of 
which developed an additional bulb from its terminal bud. Une 
species has developed a runner from a bud axillary to the foliage 
leaf, apparently being derived from the adjacent form in which 
the second runner arises from a bud axillary to the inner scale. 
The production of this lateral runner is confined to the flowering 
plants, since only in these is the leaf axil elevated above the base 
of the bulb. This form is very restricted, and appears to be the 
species most recently derived from the parent stock, or from some 
other species as these are now known. 
The general development in the genus would confi 
assumption that it is related to Tulipa, especially throu 
sylvestris. 
rm the 
gh 7. 
Jouns Hopkins UnNIveRsITY 
Battmore, Mp. 
