ANNOTATIONS AND ADDITIONS. 171 



enormous thickness of 30 to 37 (32 to 39 English) feet, in 

 diameter measured near the ground. (Emerson, Report on 

 the Forests, pp. 49 and 101). The roots present the strik- 

 ing phenomenon of woody excrescences which project from 

 3 to 4| feet above the earth, and are conical and rounded, 

 and sometimes tabular. Travellers have compared these 

 excrescences in places where they are very numerous to the 

 grave tablets in a Jewish burying-ground. Auguste de St. 

 Hilaire remarks with much acuteness : " Ces excroissances 

 du Cypres chauve, ressemblant a des bornes, peuvent etre 

 regardees comme des exostoses, et comme elles vivent dans 

 Tair, il s'en echapperoit sans doute des bourgeons adveiitifs, 

 si la nature du tissu des plantes coniferes ne s'opposoit au 

 developpement des germes caches qui donnent naissance a 

 ces sortes de bourgeons." (Morphologic vegetale, p. 91). 

 A singularly enduring power of vitality in the roots of trees 

 of this family is shown by a phenomenon which has excited 

 the attention of vegetable physiologists, and appears to 

 be of only very rare occurrence in other dicotyledonous 

 trees. The remaining stumps of White Pines which have 

 been cut down continue for several years to make fresh layers 

 of wood, and to increase in thickness, without putting forth 

 new shoots, leaves, or branches. Goppert believes that this 

 only takes place by means of root nourishment received by 

 the stump from a neighbouring living tree of the same 

 species; the roots of the living individual which has 

 branches and leaves having become organically united with 

 those of the cut tree by their having grown together. 

 (Goppert, Beobachtungen iiber das sogenannte Umwallen 



