CHAPTER XV. 



MISCELLANEOUS BOTANICAL LETTERS. 

 1873-1882. 



[THE present chapter contains a series of miscellaneous let- 

 ters on botanical subjects. Some of them show my father's 

 varied interests in botanical science, and others give account 

 of researches which never reached completion.] 



BLOOM ON LEAVES AND FRUIT. 



[His researches into the meaning of the " bloom," or 

 waxy coating found on many leaves, was one of those in- 

 quiries which remained unfinished at the time of his death. 

 He amassed a quantity of notes on the subject, part of which 

 I hope to publish at no distant date.* 



One of his earliest letters on this subject was addressed in 

 August, 1873, to Sir Joseph Hooker : 



" I want a little information from you, and if you do not 

 yourself know, please to enquire of some of the wise men of 

 Kew. 



" Why are the leaves and fruit of so many plants protected 

 by a thin layer of waxy matter (like the common cabbage), 

 or with fine hair, so that when such leaves or fruit are im 



* A small instalment on the relation between bloom and the distribu- 

 tion of the stomata on leaves has appeared in the ' Journal of the Linnean 

 Society/ 1886. Tschirsch (Linntza, 1881) has published results identical 

 with some which my father and myself obtained, viz. that bloom dimin- 

 ishes transpiration. The same fact was previously published by Garreau 

 in 1850. 



