THE AMERICAN BOTANIST 25 



belt is the Pacific Province. The southern part has a cHmate 

 Hke that of Mediterranean countries; the northern, like that of 

 of Scandinavia. There are relatively small seasonal changes 

 either in the cool and humid north, or the dry and warm south. 

 The point concerning all this that is of interest to botanists, is 

 that each Province has a fairly distinct flora of its own. Soil. 

 elevation, and other minor factors may influence the relative 

 abundance and local distribution of a species, but it is climate 

 as a whole that controls the range of the majority and makes 

 distinct floras recognizable. 



Resistent Chestnuts. — The chestnut blight, discovered 

 in New York City in 1904, has since swept aw^ay practically 

 all the chestnut trees from an area extending from New York 

 and New Jersey to Centrol Pennsylvania and Northern Vir- 

 ginia and is still spreading. Chestnut forests of commercial 

 importance occur in seventeen States but there appears to be 

 no wav bv which the disease can be controlled and the nine- 

 teen billion feet of this timber still standing seems to be 

 doomed. Whether the chestnut tree is likelv to become ex- 

 tinct or not is another matter. According to E. R. Hodson in 

 the Journal of Forestry, there are signs that trees in the in- 

 fected regions are developing an immunity to the disease and 

 that these immune plants may revive and produce a race of re- 

 sistant trees. Chestnut wood and bark have a number of im- 

 portant uses and the possibility that the mountains in the Al- 

 leghany region where the disease has wrought the greatest in- 

 jury may be reforested with resistant trees is one likely to give 

 foresters much encouragement. 



Sensitive Stigmas. — A number of plants are known 

 which have sensitive stigmas with lobes that close when 

 touched. This feature has usually been considered a device for 

 retaining the pollen when brushed from a visiting insect, but 

 F. C. Newcombe recently reported that the closing of the stig- 



