286 APPENDIX 



and layers of ash reaching on an average a thickness of thirty metres, and 

 frequently sixty metres.'^ Of course all life on the islands was extinct. 

 When Treub in 1886 first visited the island, he found that blue-green algae 

 were the first colonists on the pumice and on the exposed blocks of rock 

 in the ravines on the mountain-slopes. Investigations made during sub- 

 sequent expeditions demonstrated the association of diatoms and bac- 

 teria " [with the algae]. "All of these were probably carried by the wind. 

 The algae referred to were according to Euler of the nostoc type. Nostoc 

 does not require sugar, since it can produce that compound from the CO^ 

 of the air by the activity of its chlorophyll. This organism possesses also 

 the power of assimilating the free nitrogen of the air. From these obser- 

 vations and because the NostocacecB generally appear as the first settlers 

 on sand the conclusion ^has been drawn that they or the group of Schizo- 

 phycece to which they belong formed the first settlers of our planet." 2 



NOTE III 



ONE SECRET OF LIFE— SYNTHETIC TRANSFORMATION OF INDIFFERENT 



MATERIAL^ 



"The essential difference between living and non-living matter con- 

 sists then in this: the living cell synthetizes its own complicated specific 

 material from indifferent or non-specific simple compounds of the sur- 

 rounding medium, while the crystal simply adds the molecules found in 

 its supersaturated solution. This synthetic power of transforming small 

 'building stones' into the complicated compounds specific for each or- 

 ganism is the 'secret of Hfe' or rather one of the secrets of life." 



NOTE IV 



INTERACTION THROUGH CATALYSIS — THE ACCELERATION OF CHEMICAL 



REACTIONS THROUGH THE PRESENCE OF ANOTHER SUBSTANCE 



WHICH IS NOT CONSUMED BY THE REACTION* 



"The discovery of Lavoisier and La Place left a doubt in the minds 

 of scientists as to whether after all the dynamics of oxidations and of 

 chemical reactions in general is the same in living matter and in inanimate 

 matter. . . . The way out of the difficulty was shown in a remarkable 

 article by Berzelius.^ He pointed out that in addition to the forces of 



^ Ernst, A., The New Flora of the Volcanic Island of Krakatau, Cambridge, 1908. 



" Euler, H., Pflanzenchemic, 1909, ii and iii, 140. 



^ Loeb, Jacques, 1916. The Organism as a Whole, p. 23. 



^Loeb, Jacques, 1906. The Dynamics of Living Matter, pp. 7, 8. 



* Berzelius, Einige Ideen iiber eine hei der Bildung organischer Verbindtingen in der 

 lebenden Naliir ivirksame aber bisher nicht bemerkte Kraft. Berzelius u. Woehler, 

 Jahresbericht, 1836. 



