26 



■rilK I'T.AXT WOULD. 



coml)iiiations. Professor lirainerd, of the Vermont I)otaiiical 

 CluL, has recently ap])lied this hitter method witli eminent sne- 

 cess to the violets, in which he finds that hyhridizations take place 

 between a large number of ])airs. The numerous diiferino' forms 

 which appear in the second <ieneration of the violet hyhrids 

 doubtless form the basis of many of the new species that have 

 been described in the last few years, and also has led to erroneous 

 conclusions as to the interiiradalion Ix'tween some of the sju'cies. 



HI. 



IV. 



VI. 



Figure 7. Plantlets grown from acorns of a tree of Bartram's Oak, which 

 bore leaves like Figure 2, III. 



Bartram's oak {(^)acrciis lieferupJtyUa), which was discov- 

 ered near Philadel))hia in l7r)t), has long been supposed to be a 

 hybrid, and its variations in the nursery has called for much 

 connnent at various times during the past twenty-five years. In 

 order to obtain some positive evidence u])on its ehni'acter, a quan- 

 tity of acorns was ])rocured from a ti'ee on Staten Island in Oc- 

 tol)er, IDOa. Upon germination these displayed all of the phe- 

 nomena of alternative inheritance, the seventy-five plantlets ob- 

 tained including some which bore leaves exactly duplicating the 

 willow oak (Q. Pltellos) one of the ancestors, while one or two 

 were equally closely similar to the red oak (Q. rithra), the other 

 supposed mend)er of the original cross. The remaindei' of the 

 ])rv>geny could be arranged in a series bet\\cen these two poles, 

 A\'ith the ancesti'al ([ualities variously displayed. 



