this false Alba. I would gladly have worked on the oaks, because I found that one can 

 easily and exactly dif ferentiate South European varieties, which are very similar, 

 like Hex Suben, Pseudosuben , forms of infectcriafoccidentalis , according to the branch 

 cross-section, besides through buds, leaf cross-section. But I will first have to be 

 finished with the conifers, as far as this is possible with the microscope. The firs 

 show nice differences, in that the West-American also have Stigmas on the upper side; 

 of the East-American, balsamea has only one row of stigmas on the upper side. The 

 spruces show few differences. The larches and cedars, on one and the same species 

 have greater differences between the needles of the long and the Short shoots than the 

 ptopotyionate needles of different species. In Europe, that is in the Alps, there 

 definitely are various kinds of larches. All in all, after having collected through 



two years Pinus silvestris , Pumilio , Cembra excelsa , Abies pectinata , Lanix 



europaea, Betula alba and pubescens , Fraxinus excelsior , Acer platanoides , Pseudoplatinus 

 Campestre, Quercus pedunculata , Cerris , pubescens , sessiliflora and other distributed 

 tree varieties of all to me to me accessible locations of the Carpathians, Sudetes, the 

 Tyrolean, Krain Alps, the Vosges, the Harz and Thuringian, the Polish and Hungarian 

 plains and from East Prussia, Hessia, Serbia, Croatia, I have come to the conclusion 

 that of each of these so-called varieties there are a number of strains, that remain 

 constant under the most different cliraatic and soil conditions, on the other hand in 

 one and the same position all occur together (in Hungary much more than in Germany) . 

 However, these completely different strains do not show any perceptible microscopic 

 signs (except perhaps the oaks in the wood, some spruces in the bark) and I doubt that 

 I will bring it further than at the most to form exact groups. 



Pumilio in all of the strains belonging to silvestris are widely different in 

 their mocroscopic structure whereas young seedlings or branches of the obligua ( Pumilio ) 

 and the Frieseana (silvestris) are confusingly quite similar. It would appear to me 

 now that Coulteri with australis , pungens , cubensis belong in a group, which is charac- 



terized by ducts on the vascular tissue. Do the cones and male flowers of 



pun^ens Coulteri australis cubensis agree with this view? Unfortunately I am somewhat 

 uncertain in regard to several varieties because with two shipments from you the 

 numbers repeated, and that, where it pertains to 3 needles like ponderosa and Coulteri , 

 is very ticklish. Also of Coulteri I reeceived only very few spontaneous needles 



(cultivated ones are often much too 

 uncertain in their designation) and 

 therefore I am not quite sure of this 

 kind which is excellent in the cone. 



australis 



ponderosa 





group 



group 











1 2 3 



4 5 6 7 8 9 10 



Missouri 



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