MITELLASTEA AND BUBACEB. 235 



in each. In a word, the character of Bossekia, as Necker really 

 gave it, excludes from the genus completely every Ruhus known 

 at that time save R. odoratus alone. Yet Mr. Eydberg says : 

 "There is nothing in Necker's diagnosis that points directly to 

 R. odoratus. It is only by inference that any one may come to 

 the conclusion that that species is intended." The first sen- 

 tence of this is already on my list of absolute falsities ; nor do 

 I think the cause of truth and science can ever demand its re- 

 moval thence. But now a word upon the philosophy of that 

 delectable phrase, " only by inference." 



One side of the moon Mr. Eydberg and I, under favorable con- 

 ditions, may see to be a hemisphere. The other side of it 

 we shall never see or be able to visibly match with the hemi- 

 sphere we do see (as we might match two different specimens of 

 Rubacer) . Do we know that the moon's invisible side has a convex 

 and not a plane surface? Assuredly we do know it, and 

 as certainly, "only by inference." Do we know that this 

 planet whereon we botanize is spherical ? Its sphericity no man 

 ever saw or will see. "We do know it a sphere, but " only by 

 inference." Why have learned men and masterly botanists, 

 Linnaeus, Jussieu, Endlicher, Bentham, Gray, and some hun- 

 dreds more — why have they published thousands of plant genera 

 by diagnosis only, citing not a type? Solely for the convenience 

 of those who, competent to use such books, infer to a certainty 

 the generic identity of things from those diagnoses alone. Did 

 my friend when he published the Rubacer diagnosis not expect 

 each possible finder of an unknown species of it, if a botanist, 

 to be able to infer to a certainty the genus from his description 

 alone ? If not, then he wastes time, ink and paper in writing 

 diagnoses; for these are then a dumb show; a useless mere for- 

 mality. What use in a Gray's Manual, a Britton's Manual, a 

 De Oandolle's Prodromus, or any of the untold thousands of 

 other such books, but through this, that untold thousands of 

 educated people, competent to use them, may infer to a certainty 

 the genera and the species by the diagnoses alone ? 



This " onlj an inference ' ' compels the inference of sorry limi- 



