412 



BOTANY 



[CHAP. XI 



Letter 739 By all the rules of right the leaves of the logwood ought 

 to move (as if partially going to sleep) when syringed with 

 tepid water. The leaves of my little plant do not move at all, 

 and it occurs to me as possible, though very improbable, that 

 it would be different with a larger plant with perhaps larger 

 leaves. Would you some day get a gardener to syringe 

 violently, with water kept in a hothouse, a branch on one of 

 your largest logwood plants and observe [whether?] leaves 

 move together towards the apex of leaf? 



By the way, what astonishing nonsense Mr. Andrew 

 Murray has been writing about leaves and carbonic acid ! 

 I like to see a man behaving consistently. . . . 

 What a lot I have scribbled to you ! 



Letter 740 



To W. Thiselton-Dyer. 



[Aug., 1877.] 



There is no end to my requests. Can you spare me a 

 'good plant (or even two) of Oxalis sensitiva ? The one which 

 I have (formerly from Kew) has been so maltreated that I 

 dare not trust my results any longer. 



Please give the enclosed to Mr. Lynch. 1 The spontaneous 

 movements of the Averrkoa are very curious. 



You sent me seeds of Trifolium resupinatum, and I have 



raised plants, and some former observa- 

 tions which I did not dare to trust have 

 proved accurate. It is a very little fact, 

 but curious. The half of the lateral 

 leaflets (marked by a cross) on the 

 lower side have no bloom and are wetted, 

 whereas the other half has bloom and 

 is not wetted, so that the two sides look 

 different to the naked eye. The cells 

 Fig. i 3 ._ Leaf of Trifoiium of the epidermis appear of a different 

 resupinatum (from a shape and size on the two sides of the 



drawing by Miss Pertz). j^ rp. -, 



When we have drawings and measurements of cells made, 



1 Mr. Lynch, now Curator of the Cambridge Botanic Garden, was at 

 this time in the R. Bot. Garden, Kew. Mr. Lynch described the move- 

 ments of Averrhoa biliinbi in the Linn. Soc. Journ., Vol. XVI., p. 231. 

 See also The Power of Movement in Plants^ p. 330. 



