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THE AMERICAN BOTANIST 



tiiic American are inclined to think that the reflection of ultra- 

 violet light has the same purpose as the reflection of visible 

 light, that is, the attraction of insects. It is well known that 

 ants can see in ultra-violet light and it is quite likely that other 

 insects have the same ability. While there is no difference that 

 llie eye can note between flowers that reflect and those that ab- 

 sorb ultra-violet light, the experimenters found that when an 

 ultra-violet flower is placed in a beam of ultra-violet light, the 

 reflected rays when allowed to strike a sheet of white paper 

 moistened with acid cjuinine sulphate caused the alkaloid to 

 become highly luminous while other flowers make no impres- 

 sion upon it. In this connection it may be well to call attention 

 to a note in this magazine for November, 1913, in which a 

 number of flowers are mentioned which, to the eye, are clear 

 yellow, but which come out in two colors in a photograph. 

 Possibly the areas of different color may reflect the ultra-violet 

 light in different proportions. 



Formation of Starch by Plants. — In elementary 

 botanical courses we are usually told that the plant forms 

 starch in the leaves by the union of carbon dioxide and 

 water in the presence of sunlight, but it appears that this 

 process is not quite so simple as this explanation might 

 lead one to think. According to a writer in Science, this is 

 what really happens : "During the formation of starch 

 through the agency of chloroplast or leucoplast we con- 

 ceive that there is instituted a predetermined, orderly in- 

 dependent and interdependent series of reactions the first 

 of which is manifested in an interaction between water 

 and carbon dioxide through the agency of an enzyme in 

 the formation of an oxidase to form formaldehyde. Dur- 

 ing this process .there is formed another enzyme which 

 tentatively may be designated as an aldehydase that re- 

 acts with the formaldehyde and by polymerization and con- 

 densation of six molecules gives rise to a simple sugar 



