228 NOTES AND COMMENT 



the forester. Hiilier estimates the number of species of seed plants in 

 the Amazon basin as not more than 20,000, of which 10,000 are woody 

 plants. Of these 10,000 woody forms he states that not more than 2500 

 can be considered as trees. The number of dominant trees that form 

 the canopy of the dense forest would be much less. It means that there 

 is a possibility of dividing this poorly known region, which is a part of 

 the so-called tropical rain forest formation, into a number of different 

 formations, just as the coniferous forests of the west are so divided, and 

 of giving them the names of dominant species or genera. 



It is believed that many of the problems in the study of vegetation 

 in the temperate regions cannot be successfully solved until we have 

 more and better knowledge of tropical vegetation. We are now inter- 

 preting temperate and tropical vegetation in terms of temperate con- 

 ditions. With a better knowledge of the vegetation in the regions 

 where ecological conditions reach their optimum, I am convinced 

 that many of our "provincial temperate ideas" about ecology will be 

 greatly modified. — H. N. Whitford. 



In the recently issued eighth volume of the Bulletin of the New 

 York Botanical Garden Mr. Percy Wilson has contributed a paper on 

 the Vegetation of Vieques Island, which lies between Porto Rico and the 

 islands recently acquired by the United States from Denmark. The 

 word vegetation is not used in the title of this paper in its commonly 

 accepted sense, since the text gives only a brief page to that subject 

 and is mainly devoted to a list of the flora. The energetic explorations 

 of the New York Botanical Garden are adding rapidly to our knowledge 

 of the flora of the smaller as well as the larger of the West Indian 

 islands, and it is to be hoped that this knowledge will soon be utilized 

 in connection with further investigations of the vegetation of these 

 islands. 

 <« 



Among the papers appearing in subsequent issues of The Plant 

 World will be the following : Soil Temperatures as a Factor in Phyto- 

 pathology, by Prof. L. R. Jones; The Beginnings and Physical Basis of 

 Parasitism, by Dr. D. T. MacDougal; The Indicator Significance of 

 Native Vegetation in the Deterixdnation of Forest Sites, by Mr. Clar- 

 ence F. Korstian; The Adaptation of Truog's Method for the Deter- 

 mination of Carbon Dioxide to Plant Respiration Studies, by Mr. A. 

 M. Gurjar; and The Interpretation and Apphcation of Certain Terms 

 and Concepts in the Ecological Classification of Plant Communities, 

 by Dr. George E. Nichols. 



