670 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Chemical Changes. 



Enzymes of the Tea-leaf.* — H. H. Mann has investigated the 

 nature of the changes which occur during the preparation of the tea- 

 leaf and comes to the following conclusions: — (1) That an oxidase 

 occurs in the leaf. (2) That this oxidase is the chief agent in bringing 

 about the fermentation and colouring of the leaf. It is most active 

 below 55° C. and is destroyed about 80° C, is very sensitive to acids 

 and also to alkalies, but not to quite the same extent. There is distinct 

 evidence that part of it usually occurs as a pro-enzyme in the leaf. 

 (3) That it occurs in greatest quantity in the unopened tip-leaf of the 

 shoot, and that the quantity decreases as the leaves get older, but that 

 the stalk contains at least the same amount as the tip-leaf. (4) That 

 leaf which contains the most enzyme makes the most highly flavoured 

 tea. The increase of enzyme in the leaf seems in some way connected 

 with the amount of phosphates in the soil. (5) The amount of enzyme 

 in the leaf materially increases during withering, a fact which throws 

 a new light on the nature of the process, and makes it probable that 

 the enzyme performs much more important functions in the manufacture 

 than has hitherto been supposed. Other enzymes occur in the leaf, but 

 there is at present no evidence that they play an important part in tea 

 manufacture. 



General. 



Liparis Loeselii and Teucrium Scordium.t — A. Bennett gives 

 notes of the occurrence and distribution of these two East Anglian 

 marsh plants, which are becoming gradually rarer as drainage and 

 cultivation extend. 



Variations in Perianth of Ranunculus Ficaria.J — W. A. Nichol- 

 son gives a table of statistics showing the variation in the numbers of 

 the sepals and petals in 2116 flowers of B. Ficaria from Norfolk, and 

 works out the standard deviation from the mean by the method recom- 

 mended by Prof. Pearson. That for the sepals is ■ 4776, for the petals 

 - 9538. He finds that as the sepals increase the petals decrease in 

 number. 



Albinism in Plants.§ — E. Pantanelli publishes some researches 

 into the meaning of albinism in plants. After reviewing the papers 

 of previous authors he proceeds to the anatomical side of the subject, 

 and considers first the relation between the white patches and the 

 nervation and deformation caused by albinism ; and secondly, the dis- 

 tribution of the chromatophores in the white leaves. He has studied 

 some eighteen species. In summing up his results he finds that the 

 diversely coloured areas are always bordered by nerves ; that the pali- 

 sade cells are the first to turn white ; that the thickness of the leaf is 

 usually as great in the white patches as in the green ; that the distribu- 

 tion of the chromatophores is subject to great specific variation ; that in 

 white patches the chrornatophores are absent, in yellow patches they 



* Journ. Asiat. Soc. Bengal, lxx. pt. ii. (1902) pp. 154-66. 



t Trans. Norf. and Norw. Nat. Soc, vii. (1902) pp. 333-8. ' 



% Tom. cit., pp. 379-82. 



§ Malpighia, xv. (1902) pp. 363-415 (1 pi.). 



