Hegelmaier 

 Ree. Jan. 26,186? 

 Ans. Jan. 27 



Tubingen Dec. 18, 1866 



Möst Honored Sir Doctor ! 



I can impossibly avoid to thank you for two letters, which 

 came during the J.ast months, before the year comes to an end*. for the 

 transactions of the Academy of Science, which came to me by way of the 

 local university library, and ,then, for the american water-lenses 

 ( this is ^e«^^^t the German for ,, Lemna ,, f E.D.), which came to rae 

 through 1 Prof . Biraun.. 



From a notation in the first I learned und er announcements, , 

 that a dissertation by you about Callitrlche has been advanced- f or 

 printing (and , most likely, has been printed in the meantime) • II hope,, 

 to be able, to send to you in the not too distant future a small theme 

 of the same subject, which has been sent for some time to be printed, 

 and, in which I have tried to combine the results of a gradual cross- 

 section v of a number of collections and supports from you and other 

 sources about questlonable problems. General questions are little tou- 

 ched here, but the reasons, which forced me to retain the grouping into 

 two sections,and, which I hope will obtain your approval in connectiorr 

 with the related illustrations. Unf ortunately, I have up to now not 

 succeeded;to achieve for the New-Holland species, which are especially 

 important in this relation-,a distributionv not only for my collec- 

 tions,; much less so for publication (verbatims ,, distribution w E.D. ). 

 Should this come to pass in the future, I shall not fail, to get sam- 

 ple s to you. As to the number of aeeepted species, I will probably be 

 not in harmony with you, as I» strived for a maximal contraction, how - 

 ever, I am convinced, that arbi trar|ness has much leeway in this point, 

 and differences are thus of little consequence, . 



The examination of the Lemnaceae gave me much pleasure; repre- 

 sented are L ] > <j £i5i<lca^ polyrrhlza ( s» umbonata A.Brn. a difference does 



