January, 1938 



EVOLUTION 



Page Thirteen 



which to unlock one of the doors to 

 the mystery of life itself. 



When Dr. Stanley reported on his 

 work with tobacco mosaic virus about 

 a year ago he expressed the hope that 

 the viruses that cause diseases in ani- 

 mals and man would also yield to the 

 technique he had developed. Success 

 has now crowned this effort. 



Other scientists of the Rockefeller 

 Institute, including Dr. Carl Ten 

 Broeck and Dr. Thomas G. Wyckoff, 

 have now isolated the virus that causes 

 equine encephalitis, a horse disease 

 similar to human sleeping sickness, 

 and the virus causing warts on rabbits. 

 Both of these viruses are also giant 

 protein molecules, but they differ 

 enough so that each causes only its own 

 peculiar disease. 



It seems probable that certain dis- 

 eases have their origin in the mutation 

 of some protein molecules from their 

 ordinary harmless forms into forms 

 that are harmful. Again, certain vir- 

 uses that produce disease in one plant 

 are harmless to other forms of life. 

 Dr. Stanley reports that the virus 

 which causes ring disease in tobacco 

 also exists in the potato, but does no 

 harm, either to the potatoes or to the 

 humans who eat them. 



It has also been discovered already 

 that by certain chemical methods these 

 virus proteins can be rendered inactive, 

 but still capable of giving immunity. 

 Thus an entirely new road to the study 

 and conquest of certain diseases opens 

 up. 



"The sole objection" says Dr. Stan- 

 ley, "to the final and complete accep- 

 tance of virus proteins as protein mole- 

 cules is that, although an analogy of a 

 protein reproducing itself in the test 

 tube is known, the self-production of a 

 protein in the living cell is today not 

 an accepted chemical reaction. Imme- 

 diately we are forced to the inside of a 

 living cell we are faced with a set of 

 conditions that we have not fathomed 

 as yet. The virus protein is apparently 

 imbued with something of which today 

 we are ignorant. 



"Knowledge of the mechanism by 

 means of which a given huge mole- 

 cule-like protein, when introduced in 

 a certain cell, is able to bring about the 

 organization of the amino acids and 

 cellular constituents, with formation 

 of exact duplicates of the introduced 

 entity, is of tremendous importance, 

 for this mechanism is the basis of bio- 

 logical activity. 



"The virus proteins, because of their 

 abundance and stability, furnish us 

 with adequate working material for a 

 study of this mechanism." 



What Snares 

 Sun-Energy? 



EVERY school boy has heard that 

 chlorophyll makes plants green, 

 and that by means of chlorophyll the 

 energy of sunlight turns water and 

 carbondioxide into plant substance, 

 thus creating the primary food upon 

 which all animal and human life de- 

 pends. 



Now comes Dr. Ondess L. Inman, 

 director of the Charles F. Kettering 

 Foundation for the Study of Chloro- 

 phyll at Antioch College and tells us 

 that this is not quite correct. No scien- 

 tist knows as yet exactly what chloro- 

 phyll is and just how it does this work 

 of turning inanimate matter into living 

 substance, without which none of us 

 could exist. But in common with a 

 great many other research workers Dr. 

 Inman fias been studying this matter, 

 and he has just found out something 

 that no one knew before and that may 

 prove to be of tremendous importance 

 to the future of the human race. 



He has discovered that the extracted 

 chlorophyll, which is being studied in 

 the laboratories is not quite the same 

 as the chlorophyll as it exists in the 

 green plant, and that there is another 

 substance within the chlorophyll of liv- 

 ing plants that serves as the actual 

 harnesser of the sun's energy. This sub- 

 stance seems to be destroyed in the 

 chemical process of chlorophyll extrac- 

 tion, but he has proved its existence 

 by means of the spectroscope and also 

 by various chemical tests. But he has 

 not yet succeeded in "isolating" it, so 

 that we can not yet be sure about its 

 nature. Dr. Inman says that it appears 

 to have a relation to the chlorophyll 

 similar to that of the protein molecule 

 globin to the hemin in the blood, 

 forming the more complex hemo- 

 globin, and that it probably consists of 

 a protein and a fat. 



A high speed ultra-centrifuge will 

 now be used to "isolate" this newly 

 discovered substance from the chloro- 

 phyll. This process is a little like that 

 of the common cream-separator, which 

 "isolates" the cream from the milk. 

 This is the same apparatus with which 

 the scientists at the Rockefeller Insti- 

 tute for Medical Research have isolated 

 the tobacco mosaic virus and proved it 

 to consist of extra large protein mole- 

 cules. 



If this experiment is successful it 

 may have far reaching consequences. 

 It may enable us to learn how to do 

 artificially this work done by green 

 plants of storing up the sun's energy, 

 and how to make starches and sugars 

 out of inorganic materials. 



The Shasta Daisy 



By Garnett Russell Bright 



EXPERIMENTING with the Amer- 

 ican daisy many years ago, Luther 

 Burbank noticed that one bush had 

 whiter blossoms than any other of the 

 thousands that he had cultivated. With 

 this plant Mr. Burbank began fifteen 

 years of effort to produce a daisy of 

 the purest imaginable white. 



First he crossed the American ox-eye 

 with its English cousin by taking pollen 

 from the English daisy and fertilizing 

 the American daisy. Flowers from 

 the seed thus produced were larger 

 and bloomed earlier than either parent, 

 but all had a yellowish tinge instead 

 of the pure white that he wanted. 



Next he crossed this hybrid with 

 the German ox-eye, which made only 

 a slight improvement. After five or 

 six years of selecting the best of this 

 hybrid with its three parents he suc- 

 ceeded in raising a much superior 

 daisy, larger and more beautiful m 

 form and just as rugged and prolific, 

 but still lacking the snowy whiteness. 



Then he learned of an Asiatic daisy, 

 a coarse plant with an ugly leafy 

 flower, which had the quality he want- 

 ed: it was pure white. He obtained 

 seed of this daisy from Japan, brought 

 it into blossom and crossed the pollen 

 with his best hybrid daisy, the product 

 of three parents and many years work. 

 The first season's bloom from these 

 seeds were disappointing, but the sec- 

 ond season one plant had flowers as 

 beautifully white as the Japanese daisy, 

 larger than the largest ever brought 

 into blossom. It also had the grace 

 of the American plant and was as vig- 

 orous and hardy as any of the four. 



Each year for several years he raised 

 thousands of seedlings having these 

 four ancestral strains from three con- 

 tinents, kept the best plants each season 

 and destroyed the others, until at last 

 the wonderful flower known as the 

 Shasta Daisy was produced. 



Having succeeded in this, Mr. Bur- 

 bank proceeded to cultivate slight dif- 

 ferences in his various blossoms until 

 now the Shasta Daisy has several 

 strains. The Alaska has larger and 

 more numerous blossoms and longer 

 stems than the original or parent Shas- 

 ta. Westralia has blossoms of even 

 greater size and very long stems. 



It is true that these variations have 

 arisen under artificial conditions ; but 

 it is also true that there is nothing in 

 these conditions that may not also oc- 

 cur in nature. 



