118 THE JOURNAL OF BOTANY 
two kept in the dark; reactions confirmed the previous results. 
These experiments clearly show that the decomposition of 
chlorophyll is accompanied by the formation of an aldehyde and 
of something able to oxidize the potassium iodide and to set free 
the iodine. Ifthe chlorophyll papers are exposed behind coloured 
filters, we find that both the aldehyde and the potassium iodide 
reaction are much stronger in the red than in the blue, and are 
Se aur in the green, but if the exposure behind the green and 
blue is prolonged to eight or ten times that of the red, the re- 
action in the blue becomes as strong as that in the red. Instead 
of alcoholic extract of chlorophyll we may use dried leaves, or 
chlorophyll expressed from leaves, or layers of Euglena, or alge 
spread over the paper. The reactions also take place inside a 
leaf, if the bleaching has been efficient. Thus if sunlight is 
bl m 
area, and if treated with Schiff’s solution, a sieopg aldehyde 
was the case in the present series of experiments, but the author 
was not able to satisfy himself on this point, sie several of 
the tests succeeded even with so small an amount as one-millionth 
a d 
photo-decomposition of chlorophyll takes place only in the 
presence of oxygen; that carbon dioxide need not be present to 
stances are present, associated especially with t and 
xanthophyll upon which the activity of the chlorophy ein 
depends. 
A. W. 
Marah, with its remarkable gertuination. He stated that the 
genus Marah includes some eleven eg: prapoent confined to 
the Pacific ‘watershed of the W. States of N. America and the 
islands of Lower California. The ate is ‘aletinpnistiod from 
Echinocystis ae collins genera with similar floral characters by i 
enormous tuberous root, associated with which is the peculia 
mode of germination of the seeds. The petioles are fused to form 
maining hypogeal. The plumule finally bursts through the 
petiolar tube, and grows up into the air with sharply bent-over 
