SCIENTIFIC COMMITTEE. 



xxxix 



able number of varieties, and provides an interesting example of 

 variation in a weed of cultivated land having apparently a rather 

 restricted range. He also showed a fruit of a small Pineapple from 

 Pernambuco, which grew and fruited in a cool greenhouse at Islewortli. 



Vegetative Hnds in Inflorescence oj Tacca cristata. — Mr. W. Hales, 

 A.L.S., showed inflorescences of Tacca cristata in each of which a bud 

 had produced a rosette of leaves with a small tuber at the base, very 

 similar to that of the Hedychium shown by Mr. Elwes on December 15, 

 1914. See Journal R.H.S. 40, p. clxxxiii. 



The Chemistry oj Flower Colours. — Dr. F. Keeble, F.R.S., gave an 

 account, illustrated by experiments, of the present state of our know- 

 ledge of the chemical nature of flower pigments. It was demonstrated 

 that an extremely close relation exists between the anthocyan pig- 

 ments of the flower and oxydases. Such a parallelism lends support 

 to the view that the anthocyan pigments are due to the action of 

 oxydases on chromogens. It was shown, however, that anthocyan- 

 like substances have been produced by various experimenters, not by 

 the oxidation, but by the reduction of substances which occur in 

 plants. To reconcile these two divergent phenomena Dr. Keeble 

 pointed out that the action of an oxydase may involve not only the 

 oxidation of a given substance, but the simultaneous reduction of 

 another. At the conclusion of the lecture specimens of the anthocyan 

 pigments as prepared by Willstatter and Everest were exhibited. 



Scientific Committee, February 16, 1915. 



Mr. E. A. Bowles, M.A., F.L.S., F.E.S., in the Chair, and eight 



members present. 



Variation in Orchid Seedlings. — Mr. G. Wilson, F.L.S., showed on 

 behalf of Messrs. Charlesworth & Co. a number of flowers of Odontioda 

 X ' Brunette ' to illustrate the remarkable range of variation shown 

 by the seedlings from one seed-pod. The following represents the 

 chief variations in colour, but variation was also to be seen in the 

 form and size of lips and segments : (1) Dark, bright purple, with 

 pale markings on lip just within the margin ; segments dark, bright 

 purple. (2) Dull purple, with more pale markings in same place ; 

 segments dull purple. (3) Still deeper purple, with same markings ; 

 segments deep purple. (4) Lip reddish-purple with pale markings 

 within margin ; segments purple, yellow-tipped, with few narrow 

 yellow lines. (5) Lip with red-brown spotting on disc, sprinkled 

 with same on lower half, and purple-tinted along margin ; segments 

 similar to last, but yellow streaks more abundant and no yellow 

 tip. (6) Like (1), but with white streaks and white margins to seg- 

 ments. (7) Lip heavily spotted with reddish-brown purple at tip ; 

 segments red-brown with yellow lines ; inner yellow-margined. 

 (8) Lip spotted purple, lower half white ; segments yellow-tipped, but 

 ground cream with heavy purple blotches. (9) Red-brown, and 



