236 PROCEEDINGS OF THE ACADEMY OF 



taken a genus consisting of only one species in a given locality, to 

 show how great is the variations in form, where no congenital 

 species could mix with it. I have, for this, chosen Epigaea repens, 

 Chrysanthemum leucanihemum, and the Qtiercus neo-mexicana (Q. 

 Gunnissonii ?) of the Rocky Mountains papers which most of 

 the readers of this will probably remember. Another familiar 

 plant to illustrate this is the common yellow toad flax, Linaria 

 vulgaris. In a handful of specimens gathered in an afternoon's 

 walk. I find the following marked variations: 



In regard to the spur, which is generally as long as the main 

 portion of the corolla, some have them only one-third or one-fourth 

 as long; and in one instance the plant bears flowers entirely 

 apurless. Dr. James Darrach, a member of the Academy, informs 

 me that he believes he has, in years past, gathered a spurless form, 

 but has neglected to place it on record. Then some plants bear 

 flowers with spurs thick, and others with narrow ones ; and wdiile 

 some have spurs quite straight, others curve so as to describe 

 nearly the half of a circle. The lobing of the lower lip is various. 

 In some cases the two lateral ones spread away from the small 

 central one, leaving a free space all around it ; at other times they 

 overlap the central one so that it is scarcely seen. Sometimes the 

 small central lobe is nearly wanting often not more than half 

 the depth of the two large lobes, and at times quite as full, 

 when it may be linear, ovate, or nearly orbicular. The palate, 

 as the deep colored process attached to the lower lip may be 

 called, also varies. In color it is pale lemon, but often a brilliant 

 orange. Sometimes it is but about the eighth of an inch in 

 thickness ; at others one-fourth, in flowers of the same size. In 

 the case of the shallow flat palate, the attached lobes are patent, 

 or even incurved ; while in the thick ones they are very much 

 reflexed. These two forms, when the extremes are selected, are 

 as strikingly distinct as two species often are. Again, the palate 

 is rounded and blunt at the apex ; at other times almost wedge- 

 shaped, or at least narrowing to a blunt point. The upper lip 

 varies in proportionate length, sometimes not extending much 

 beyond the palate, sometimes half an inch more ; then the 

 margins are sometimes bent down like the wings of a swooping 

 bird ; or upwards as in those of a rapidly descending one. Some- 

 times they are united and turned abruptly up at the apex, like 

 the keel of the garden pea. 



