308 KEAV EXGLAXD TREES IX AVlNTI';n. 



The pliotograpliic illustrations are all originals, most of tlieni 

 b}- the other author. Although one ot us is vesi:)Ousible for the 

 text and for the seleetion of the material photographed and the 

 other for the iilmlogi-aphs, we have freely eonsulted and the 

 bulletin is thei'efore to be eonsidered a joint publication. 



The order of ari'angement of the species in the text and the 

 scienlilic names follow the usage ol' ilie seventh edition of Gra3''s 

 ilaniial and the lattei- are in accoi-d with tlie rules laid down in 

 tlie Vienna Congress. Idic iigures and elescriptions given are of 

 trees for the most jtart growing wild in New England. A few 

 rarer species which occur iu A'ew England only very locally or in 

 isolated instances have been omitted fi'om illustration. In their 

 places, however, some of tlic more freifuently cultivated trees, have 

 been included because of their value for forestiw planting in Xew 

 England or because of tlieir familiarity in city ornamental plant- 

 ings. Tlie vai'icties of cultivated forms are so nunu'rous that it is 

 obviously possilile to take account of only the most common types. 

 Their inclusion, it is believed, will add to the value of the publi- 

 cation especially for its rise in cities. The keys can l)e absolutely 

 relied upon only for the species just mentioned from New England. 

 New England, including as it does the meeting gr(nind between 

 the noi'thern and southern floras, is extremely rich in the species 

 of trees represented. The bulletin, therefore, especially in its 

 descriptive text and illustrations should prove of service outside of 

 the geogi'aphicallv restricted region described. 



The final keys to the genera and to the species as well as the 

 descriptive text in galley were placed in the hands of the jn'csent 

 year's classes in Botany and Forestrv. A student after fimling 

 the s])ecies by the keys, read the twig characters in the galley 

 and signed his name opposite the s]X'cies if the description corres- 

 ponded with the twigs supplied. All of the trees described and 

 illustrated have thus Ijcen checked u]) by students and some of them 

 by as many as seventy diiferent persmis. In this way limitations 

 to the use of certain of the characters employed as means o£ 

 separating allied s])ecies have been discovered and the constancy 

 of other characters has been confirmed in so far as the material 

 available conlil allow. The greatest assistance rendered by the 

 students, however, has been in disclosing dilficulties in the use of 

 the keys, due to unfortunate choice of contrasted characters or of 



