January 14, 1931



Dr. Isaac Ochoterena,

Instituto de Biologia

Casa de Lago, Mexico, D.F, Mexico



My dear Doctor Ochoterena:



I take this first opportunity to thank you for the kind letter I received from you with its photographs in which you wish me the best for the New Year upon which we have already entered.  I reciprocate all that you say, and trust that the New Year may be to you a year fraught with blessings not only to yourself but to your family and all your freinds.  I am in the midst of work which seems to occupy every moment of my time and I find it difficult to get time enough to do everything which is demanded of me, but I still keep well, although I am beginning to feel the burden of advancing age and often in the latter part of the day become very tired.