ON THE STUDY OF PLANT ENZYMES. 145 
é.g., glycine, gives rise to the production of formaldehyde, 
ammonia, and carbon dioxide. Elements are thus available for 
the production of all manner of complex compounds and the method 
has a wide application. Starting, for example, from a mixture 
of the glucoside arbutin with glycine, it is possible, by the action 
of emulsin and an oxydase at the ordinary temperature, to obtain 
first a red compound, then a brownish black substance, as well 
as a volatile compound possessing the characteristic odour of ripe 
plums. In short, both the colour and odour of the ripe fruit are 
obtained by a biological synthesis from the glucoside and an amino- 
acid. This synthesis appears of general application and is being further 
studied. Presumably the colours produced in this manner are those 
characteristic of the fruit and leaves of the plants rather than of the 
flower petals. The interaction appears to involve the oxidation of the 
phenolic constituent of the glucoside either to an ortho- or to a para- 
quinone, the condensation to quinhydrone and the interaction of this 
compound with ammonia and formaldehyde. Meta- phenols do not 
undergo the same transformation. 
Erratic Blocks of the British Isles.—Report of the Committee, 
consisting of Mr. R. H. TippEMAN (Chairman), Dr. A. R. 
DWERRYHOUSE (Secretary), Dr. T. G. Bonney, Mr. F. W. 
HARMER, Rev. §. N. Harrison, Dr. J. Horne, Mr. W. 
Lower Carter, Professor W. J. Souuas, and Messrs. WM. 
Hitt, J. W. StatHer, and J. H. Mitton. 
EXNGLAND. 
Reported by the Rev. A. Irvine, D.Sc., B.A., and Mr. Percy A. 
Irvine, B.A. 
Localities all in the Upper Stort Valley. 
1. Thorley, Herts. (Boulder Clay.) 230 feet to 240 feet (O.D.). 
(1) Hypersthene Andesite (8 in. by 7in. by 4in., weight 12 lbs.). 
From the Boulder Clay. This is the same rock as an erratic recorded 
as ‘trap’ in the 1911 Report, from Parsonage Lane, which has been 
recognised by Mr. G. Campbell Smith, of the British Museum (Natural 
History), as “ quite comparable with some of the Cheviot andesites, and 
may be referred to that district provisionally.” Subangular, columnar, 
both blocks extensively bleached by the leaching-out of the iron in 
cee ering. Fragments of this rock not uncommon in the Rubble- 
Drift. 
(2) Coarse Phyllite (18 in. by 12 in. by 5 in.) intersected by a 
network of vein-quartz, considerably weathered with oxide of iron on 
the divisional planes. It closely resembles the rock continuous with 
the coarser type of slate of the Swithland quarries (Charnwood). 
(3) Angular slab (54 in. by 5 in. by 14 in). Fine-grained sandstone 
(coal-measures ?), pressure-scarred and coarsely striated on one surface. 
1913. L 
