Aschaffenburg, April 29, 82. 



Honored Sirl 



Your question regarding the falling off of needles from many conifers I 

 can answer to the extent that to me there is no Information known regarding the 

 histological reason for this phenoraenon f A superficial examination, for which I 

 did not have time to pursue more thoroughly, yielded that with abies excelsa at 

 the leaf base, sklerenchyrma tissue borders on very thin-walled parenchyma . 



I explain this to myself in that, with the drying of the thin-walled parenchyraa, 

 the sklerenchyma does not shrivel and thereby the Separation is caused. Glycerine 

 prevents this shrivelling. This process is not the same normal defoliation, as it 

 occurs with abies pectinata in moist air. Since I would like to pursue the matter 

 further, I can naturally not give any further details. Therefor the matter is of 

 special interest for me because I am occupied in examining the life history of the 

 fungus Hysterinum which causes the feared blight on conifers, and this problem gives 

 me the opportunity to make use of the return Services which you so kindly offered. 

 Namely on Pinus Strobus , which in some areas here is cultivated in forests, a similar 

 phenomenon was substantiated with the appearance of a different Hysterinum which does 

 not seem to be described. Since I find this Hysterinum Strobi-mihi in manuscripts 



everywhere in this country on P. Strobus , it is very important to me to know if this 

 also is found in America. Perhaps you would be in a position to send me a small 

 quantity of spontaneously fallen needles of P. Strobus . They would have to be gathered 

 at the time when the new shoots are unfolding and just now would be the most opportune 

 time; for the naked eye this fungus appears in the form of smaller blacker more shiny 

 sharply defined spots or pustules. 



I would be pleased if you were satisfied with my communication and remain, 



Respectfully, 



Prof. Dr. K. Prantl. 



