Sect. 4. Terminal lobe of lip bent underneath. 
m. Petal not half as long as the anther. Process of lip slightly triden- 
tate. (May 6th.) O. apifera, Huds., partly. 
n. Petal about equal to anther. (June 22nd.) 
It is supposed. by some botanists that many of the forms under which 
these most variable plants appear are only hybrids between a greater or 
less numberof species ; others, again, believe that though an occasional 
cross is probably a most efficient stimulus to variation, the greater part, 
if not all, of these individuals are the product of natural selection. 
EXPLANATION OF Pirate XLV.—Fig, J 1, petal of form J. Fig. J 2, 
under side of lip of form J. Fig. K 1, under side of lip of form K. 
Fig. K 2, upper side of lip of form K. Fig. L 1, upper side of lip of 
form L. Fig. L 2, under side of the same. Fig. M 1, petal of form M. 
Fig. M 2, upper side of lip of form M. Fig. M 3, under side of the 
same. Fig, N 1, petal of form N. 
