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THE AMERICAN NATURALIST [Vol. XLV 



season 160-170 days in length, and a winter with ex- 

 tended exposures below the freezing point, endure the 

 climate of the montane plantation with lower minima, 

 shorter growing seasons and more arid dry seasons, all 

 seasonal changes being much more sudden and pro- 

 nounced than those encountered in their original habi- 

 tats. Trillium, Ariscema, Roripa, Sanguisorba, Fragaria 

 and others offer examples of such survival. 



2. Perennials as above survive and thrive in the 

 equable climate of the maritime plantation in which much 

 more equable conditions are found than in the original 

 habitats — Podophyllum, Sanguisorba, Ariscema, (Eno- 

 tlura, Roripa and Fragaria. 



It is to be noted that many species of annuals and per- 

 ennials are supposed to range from the temperate low- 

 lands of New York to similar montane climates farther 

 south in the Rocky Mountain region, and also to the Pa- 

 cific coastal belt. Critical examination of material rep- 

 resenting the supposed inclusion of the species generally 

 reveals differences denoting elementary species or geno- 

 types which might be grouped together in a Linnean 

 treatment. These relationships offer some most inter- 

 esting probabilities as to derivation and dissemination 

 which may not be touched upon here. 



3. Species from the montane plantation survive and 

 show a luxuriant growth in the maritime plantation with 

 various vegetative modifications, of which Fragaria, 

 (K)iothcra, Juglans, Scrophularia, Senecio and Dugaldea 

 offer illustrations. 



4. Species from the montane plantation survive and 

 show a development somewhat atypic when carried to the 

 foot of the mountain on which they are indigenous. Ex- 

 amples are (Knothera, Juglans, Scrophularia and Fra- 

 garia. 



5. Species from the arid region about the Desert Labo- 

 ratory survive and show atypic activity in the equable 

 maritime climate. Illustrations are offered by the 

 Opuntias, Parkinsoma and Penstemon. Species from the 



