v 
He succeeded in preparing them for, and partially seeing them 
through the.press when he in turn was obliged to abandon the 
task owing to his leaving for Cape Colony in 1903 to take up his 
duties as Professor of Botany in the South African College. 
Failing other assistance, I found it impossible to carry it to 
completion till I had myself been relieved of administrative 
duties. 
It appears to me that it is of considerable interest to show what 
a vast number of forms of life of the most varied kind may exist 
together on what is relatively a microscopic speck of the earth’s 
surface. This would be in the present case even more striking if 
the enumeration were more complete than it can pretend to be. 
Some groups have not been worked at all; this is the case with 
the Diptera, and of the Hemiptera only the Coccide have been 
catalogued. Others, it is obvious, have been only touched super- 
ficially. The publication of what has been done may encourage 
working naturalists to correct errors and to accomplish, as perhaps 
has never been done yet, a complete census of every form of life 
oceurring spontaneously in a small but well-defined area. 
I am glad to take the opportunity of acknowledging gratefully 
the assistance which has been given to those who have suc- 
cessively had a hand in the work by a very large number of 
individual workers in various branches of zoology and botany. 
Some of the most important are enumerated in the following 
“Table of Contents.” I see from the mass of correspondence 
which has accumulated that there are a host of others, many 
personally unknown to me, who have cheerfully rendered the 
assistance which has been demanded of them on special points. 
I find it impracticable to specify them all individually, and can 
only beg them collectively to accept my appreciation of their aid. 
W. T. THISELTON-DYER. 
Kew, February, 1906. 
