William H. Calvin, The River That Flows Uphill (Sierra Club Books 1987, Authors Guild reprint edition 2001).

copyright ©1986 by William H. Calvin
Webbed Reprint Collection
This 'tree' is really a pyramidal neuron of cerebral cortex.  The axon exiting at bottom goes long distances, eventually splitting up into 10,000 small branchlets to make synapses with other brain cells.
William H. Calvin

University of Washington
Seattle WA 98195-1800 USA

E-book Special

In addition to reading it on the web, complete with color photos and maps, PDA fans can download and read it on the commute.

The .PDB file is available in either WordSmith (better formatted)  or in plain text. 

Day 1  
  WordSmith or  plain text
Day 2  
  WordSmith or  plain text
Day 3  
  WordSmith or  plain text

If you like it, remember to buy a book as a gift!  The nonvirtual book is available from in the Authors Guild reprint edition (2001).