( 417 ) 
introduced into the literature the expression Emissarium or outlet 
of tcater, which more clearly indicates the notion than the word 
“Hyclathode or water way”. 
It is thus evident from the second part of this communication on 
the secretion of water in the plant, that a secretion of liquid not 
only takes place in the leaves, but often also in the floral region 
and on various parts of the flower. 
These observations place in a different light the well-known pheno¬ 
menon of water-secretion in the flower-bud of plants with so-called 
water-calyces. 
Formerly we considered, that the secretion of water in the flower- 
bud was to be regarded as a useful arrangement, arisen in the 
struggle for life by natural selection, in order to protect the 
enclosed parts of the flower against dessication. 
We now see that it is related to the phenomenon of the secretion 
of liquid on the surface of the plant and that the presence of water 
in the calyx is to be explained thus, that the water secreted by the 
glands of calyx and corolla is less exposed to evaporation in the 
closed calyx and so can collect there. 
In other words, the secretion of water in the flower-bud did not 
arise because it is useful to the plant, but it may nevertheless be of 
advantage to the plant in these cases where the enclosed parts of 
the flower or the young fruits are exposed to the danger of dessi¬ 
cation. 
Chemistry. — “Contribution to the knowledge of catalyik pheno¬ 
mena”. By Prof. J. Boesekein. (Communicated by Prof. A. F. 
Holleman), 
(Communicated in the meeting of October 80, 1909). 
Through the researches of Perrier (Thesis 1896 and Comt. rend. 
118 > P- 1300) and of myself (Rec. 1900, p. 19) it has been shown 
that in the reaction of Friedei. and Crafts it is not the aromatic 
hydrocarbon but the chloride or the anhydride which is attacked 
fil *st by the aluminium chloride, as in many cases additive products 
could be isolated. These are then converted by the benzene derivative. 
Afterwards I have pointed out (Proc. 1907, p. 613) t that the formation 
of these intermediate products cannot, as such, serve to explain the 
