62 ORIGIN OF SPECIES 



of producing at the same time three distinct female forms 

 and a male ; and that an hermaphrodite plant should produce 

 from the same seed-capsule three distinct hermaphrodite 

 forms, bearing three different kinds of females and three or 

 even six different kinds of males. Nevertheless these cases 

 are only exaggerations of the common fact that the female 

 produces offspring of two sexes which sometimes differ from 

 each other in a wonderful manner. 



DOUBTFUL SPECIES 



The forms which possess in some considerable degree the 

 character of species, but which are so closely similar to other 

 forms, or are so closely linked to them by intermediate gra- 

 dations, that naturalists do not like to rank them as distinct 

 species, are in several respects the most important for us. 

 We have every reason to believe that many of these doubtful 

 and closely allied forms have permanently retained their 

 characters for a long time ; for as long, as far as we know, 

 as have good and true species. Practically, when a naturalist 

 can unite by means of intermediate links any two forms, he 

 treats the one as a variety of the other; ranking the most 

 common, but sometimes the one first described, as the spe- 

 cies, and the other as the variety. But cases of great diffi- 

 culty, which I will not here enumerate, sometimes arise in 

 deciding whether or not to rank one form as a variety of 

 another, even when they are closely connected by interme- 

 diate links; nor will the commonly-assumed hybrid nature 

 of the intermediate forms always remove the difficulty. In 

 very many cases, however, one form is ranked as a variety 

 of another, not because the intermediate links have actually 

 been found, but because analogy leads the observer to sup- 

 pose either that they do now somewhere exist, or may for- 

 merly have existed; and here a wide door for the entry of 

 doubt and conjecture is opened. 



Hence, in determining whether a form should be ranked 

 as a species or a variety, the opinion of naturalists having 

 sound judgment and wide experience seems the only guide to 

 follow. We must, however, in many cases, decide by a ma- 

 jority of naturalists, for few well-marked and well-known 



