PREFACE. 7* 
It only remains to add my regrets that so long a term has 
elapsed between the death of the gifted and amiable author 
and the appearance of his work; this is chiefly due to the fact 
that it was upwards of a year before the MSS. were placed in 
my hands, and to the heavy pressure of my own official duties, 
which has unavoidably retarded its progress through the press. 
Royal Gardens, Kew, 
May 27th, 1868. 
