OAKS AT ALDENHAM. 



197 



and faginea. Whether Mirbeckii be regarded as a species or a variety, 

 it seems to be as rare in Portugal as it is common in Algiers. Trabut 

 remarks in this connexion (I translate freely from the French) that 

 the oaks of the lusitanica group both in Spain, Portugal, and the East 

 are very variable, and a critical examination of all the types would 

 enable one greatly to reduce the recognized species and replace them 

 with varieties induced by soil or climate. Such an investigation, he 

 wisely adds, will have to be undertaken on the spot, as herbarium 

 samples are liable to lead one astray. I can only take him to mean 

 by this passage, coupled with what he had previously written about 

 the similarity to Q. Robur, and the unreliability of the characters 

 usually assigned to Mirbeckii, that he would be inclined to throw Q. 

 pedunculata, Q. sessiliflora, Q. lanuginosa, Q. lusitanica, Q. Mirbeckii, 

 and doubtless Q. conjerta, and probably other European oaks, into 

 one species ! For instance, though he does not mention it, if these are 

 to be lumped together, I don't see how the Caucasian Q. macr anther a 

 can be kept out of hotchpot, for it is very close to Q. conjerta. 



Trabut gives the following six varietal names to different types 

 which he came across in Algeria — tlemcenensis , brevipetiolata, micro- 

 phylla, fagifolia, angustifolia, subpedunculata. He then proceeds to 

 treat them as the more Eastern equivalents of the varieties of Q. lusita- 

 nica given above by Pereira, pairing off Q. M. tlemcenensis with Q. I. 

 Broteri, and Q. M. brevipetiolata with Q. I. faginea, and Q. M. microphylla 

 with Q. I. alpestris. He also speaks of this Algerian form approaching, 

 and of that one recalling, one or other variety of Q. lusitanica. 

 Enormously as one extreme of Mirbeckii foliage differs from another, 

 I believe if such an investigation of the Algerian forests as he talks 

 of were carried out, it would be possible to find intermediate links 

 between the type and all its varieties, and either to say that there 

 were over 100 varieties of the species, or preferably that the species 

 was so inconstant that it was impossible to lay down any feature 

 which could be denned as the unvarying characteristics of any named 

 variety. 



I confess that the reading of Trabut's clever paper is to produce 

 on my mind a feeling of hopelessness and confusion. Certainly it 

 tends to confirm what I had already realized, the utter impossibility 

 of determining a species by looking at its leaves, and yet leaves are 

 what the world at large goes by in forming an estimate of a tree, and 

 from the ornamental standpoint they are one of the most important, 

 if not the most important feature. 



But another and larger conclusion is forced upon me: in how 

 inchoate and undetermined a condition must the science of botany 

 still be when on the one hand we have American men of science 

 turning out new species of Crataegus as a baker does rolls, and for 

 a set-off a famous Frenchman lightly proposing to knock half 

 a dozen old-established and accepted species into one. Meanwhile 

 the unhappy amateur like myself continues his wail, " Oh, do explain 

 what constitutes a species," but, alas, nobody mentions, for nobody 



