POSTSCPaPT. 523 



of the work, on communicating their addresses to the 

 Author, and expressing a wish to receive any such sup- 

 plementary sheets, if printed. The carrying out of this 

 wish into effect must depend on life and health, and on 

 other possible contingencies beyond individual control. 

 And to some extent it must also depend on the commu- 

 nicative goodwill of those persons who may discover bo- 

 tanical facts, such as will fill up vacancies, or necessitate 

 alterations in any of the statements and figures set forth 

 in the pages of this work. Incidental examples of what 

 is required may be seen on pages 320 and 351. 



It would be hopeless to expect typographical accuracy 

 in all the vast number of figures printed in this work, and 

 particularly in this fourth volume. Errors in letters and 

 words, or in spelling and syntax, will occasionally be 

 overlooked while reading proof- sheets ; although the 

 sense and signification of sentences much assist in their 

 detection. Such assistance is wanting in the case of 

 numeral figures ; these being mostly mere symbols, not 

 mentally construed into their real meaning, during the 

 process of reading a proof-sheet ; so that the chance of 

 undetected errors becomes considerably increased ; while, 

 at the same time, a single figure set wrong may be a large 

 mis-statement of fact. The same is equally or even more 

 time in respect to the mechanical process of transcribing 

 figures for the press. In connexion with this remark, 

 the author feels it due to the printer of the Cybele, to say 

 that great care appears to have been taken to make the 

 printed figures con-ect. And the press is of course 

 nowise responsible for errors of transcription. 



A few words of explanation on the literary department. 

 In the three earlier volumes, where the author required 

 to refer so frequently to his own personal experience and 

 individual views about details, it was found convenient to 



