105 
rapidly, and to assume the tinted garb in which we are more 
accustomed to recognize them. The earlier blossoming plants, 
such asthe Blood Root, Twin Leaf, Skunk Cabbage and 77ril/ium, 
usually show their flower buds, in the fall, in a more advanced 
stage of development than those which flower later. The earlier 
flowering plants, also, as a rule have shorter stems and possess 
less foliage than those which blossom later. Perennial plants 
which do not develop flowers until in late spring or during the 
summer, of course, also possess scaly winter buds; but these 
buds only contain the earlier developing leaves; the later leaves 
and the flowers, are not formed until the scaly bud has burst 
and the growth of the year has well begun. 
The conclusion therefore seems to be, that many spring 
flowers owe their early development to a combination of circum- 
stances, already determined during the previoussummer. These 
are a decrease in the number of internodes, and hence also, of 
the leaves produced before the development of flower buds 
begins; and the early origination and rapid development of. 
flower buds in their scaly covering before winter sets in. 
It is probable, that as a rule, the ancestors of spring plants 
are to be sought in more southerly districts, where the length of 
the summer and the shortness of the winter season make elabo- 
rate winter scale protections for the buds less important. On 
the other hand, it has seemed to me that the change from a more 
southerly climate to a northern climate was not exactly calcu- 
lated to produce spring-flowering plants. It would seem more 
reasonable to suppose, that as southern plants migrated north- 
wards, the cooler climate would retard their period of flowering 
so as, at first, to make northern summer flowering plants of the 
earlier southern types. In the course of time they might adapt 
themselves to the cooler condition there found. 
However, as a plant which had become accustomed to a 
more northern climate migrated southward, the reverse condi- 
tions would operate; and a plant which did not flower until 
early in the summer farther north, would immediately become a 
spring-flowering plant on being transplanted to a warmer climate. 
It is not likely that in the migrations of plants the tendency to- 
wards northward migration is very distinct, from the inclination 
to remain in their more congenial southern homes. However, 
