578 TRANSACTIONS OF SECTION K. ~ 
groups of ferments. The ‘tyrosinase’ of the potato is also a ‘katalase,’ a 
‘peroxidase,’ a ‘ pyrogallase, a ‘hydroquinonase,’ and a ‘paraphenylendiamin- 
ase.’ It is, however, permissible to use such terms as katalase action, peroxidase 
action, and such names as laccase, russulase, potatase, carrotase, &c., as tem- 
porary names to indicate the origin of the substances whose chemical nature is 
as yet unknown. Since, however, their oxidase powers will be only one of 
many properties, it will never be advisable to name them according to these 
properties alone, any more than it*would be in the case of the metallic oxidases. 
Comparison with metallic oxidases shows that we are not even on safe ground in 
assuming the existence of specifically distinct classes of plant oxidases, such as 
phenolases, aminoxidases, and iodoxidases. The chlorides and phosphates of 
potassium and sodium are able to act as oxidase sensitisers, and thus may influ- 
ence special oxidations, or respiration in general. It is possible that they may 
exert a stimulatory or controlling action on plant metabolism and that the 
sodium chloride always present in the ash of plants may not be an entirely 
useless constituent. This may explain partly why small doses of salt stimulate 
the growth of many plants and why phosphates, in addition to being food sub- 
stances, may act as stimuli to growth. The stimulating action of many metallic 
salts on growth may be partly due to their oxidase action. 
Ursol tartrate turns lignified walls red or reddish brown. This is not an 
oxidase reaction, but is an admirable test for lignin, especially valuable for 
demonstrating the wood elements in pulpy tissue. 
Chloroform strongly and ether more feebly retard or inhibit katalase action, 
but they do not suppress oxidase action. After prolonged contact, however, the 
organic oxidases are slowly attenuated and destroyed. 
The liberation of iodine from potassium iodide may be used as a test for the 
presence of oxidases in living tissues, but does not indicate the existence of any 
power of producing peroxides. Dried organic oxidases may retain their pro- 
perties for three weeks or more, and a glycerine extract for five or more months. 
Where organic oxidases are destroyed by boiling this is probably the result 
of proteid coagulation. In spite of previous statements to the contrary, (1) 
oxidase enzymes are present in the pulp and rind of the orange and lemon, and 
in the stalks, but not in the bodies, of the endocarpal hairs; (2) oxidase enzymes 
are abundant not in the protoxylem of the carrot, but in the phloem and outer 
cortex. 
The oxidases of the beet and potato appear to be related to one another and 
to be among the strongest plant oxidases. The nearest analogies to them are 
perhaps afforded by ferric salts and ferricyanides. If the special action of apple 
oxidase on tannic acid is due to the presence of a phosphatic sensitiser, it would 
be a feebler oxidase of the same type. Carrot and parsnip oxidases are a grade 
feebler but still react to guaiacum in the absence of a peroxide. Malt diastase 
is still weaker, and papain feebler still, while pepsin may show a weak per- 
oxidase reaction with guaiacum but not any other oxidase action. 
3. Morphology and Anatomy of certain Pseudo-Monocotyledons. 
f By Miss E. N. Tuomas and A. J. Davey. 
The paper gave a preliminary account of some features of interest which 
have been disclosed in the course of an investigation into the anatomy and 
morphology of the seedlings of geophytic Dicotyledons including some pseudo- 
monocotyledonous forms. The latter have a single cotyledonary member 
terminating in a blade which is more or less bifid in Ranunculus Ficaria and 
Anemone apennina, but is undivided in Conopodium denudatum and Cyclamen 
persicum, the ‘petiolar’ region being much elongated in Conopodium 
denudatum and Anemone apennina. 
A tuberous swelling arises while the seedlings are still quite young, before 
there is any sign of a plumule, and in Cyclamen persicum even before the 
cotyledon has emerged from the seed. At an early age the external appearance 
of the seedlings is very misleading, inasmuch as the position of the tuber is 
variously related to the collet, and hence the tuber would seem to occur in 
different morphological regions. The appearance of the plumule at the apex of 
