CONCLUSION 331 



light, and others connected with electricity, which up till now 

 have been hardly suspected — the currents that traverse the 

 muscles and the nerves, or those involved in the phenomena 

 or radio-activity ; but, above all, they depend upon the 

 chemical reactions that take place between the countless 

 products of the activity or decay of structural cells. To 

 isolate these products, to determine their chemical com- 

 position, to study the action of each of them on the con- 

 stituent elements of a given organism, is a piece of experimental 

 work requiring great patience, which will probably never be 

 finished but which will certainly lead to results of the greatest 

 importance if boldly undertaken and methodically planned. 

 It is along these lines that man can hope to complete his con- 

 quest of life. This task must naturally have disheartened 

 the savants of the eighteenth century, who could not possibly 

 perceive how to set about it, but who essayed to take the place 

 of the philosophers. A beginning was made by the scientists 

 of the nineteenth century, not without a measure of success ; 

 and it has already kindled among those of the twentieth a 

 passionate enthusiasm, which the results already obtained in the 

 domain of biological chemistry must fan to a whiter heat. 



In their attempts to fathom the composition of the living 

 cell, biologists discovered first of all that it was surprisingly 

 complex, but of a nature to explain the mystery of life. 

 We have long known that the nucleus is really a complex 

 apparatus notably containing two special globules, the cen- 

 trosomes, a network of a substance that has great power in 

 fixing carmine chromatin, a network that is transformed 

 at the time of the cell-division into a festooned ribbon composed 

 of a constant number of loops in all the cells of one organism 

 and all the organisms of the same species. These loops are 

 capable of becoming isolated and then forming chromosomes. 



The botanists, in their own sphere, have recognized and 

 described the green chlorophyll granules by virtue of which the 

 plant manufactures sugar and exhales oxygen under the action 

 of the sun. They also know the leucoplasts which produce starch. 

 Within recent times discovery has been heaped upon discovery. 

 In 1887 Dr. Raphael Dubois 1 found within the plasma of cells 

 certain active and special forms to which he gave the name of 

 vacnolides ; Altmann later on called them bioplasts, and to-day 



1 R. Dubois, " Les Vacuolides," Comptes rendus de la Societe de Biologie, 

 8th ser., vol. iv, 1887. 



