l886.] NEW-YORK MICROSCOPICAL SOCIETY. 



NOTES ON PROTOCOCCUS VIRIDIS. 



BY P. H. DUDLEY. 



{Read December \Uh, 1885.) 



We have just heard the little plant under consideration classed 

 among the lowest orders of vegetation. Huxley goes further, 

 and says, '''' Protococcus and Torula (yeast plant) are the repre- 

 sentatives of the two great contrasting types of the beginning 

 of plant life." Though each is of but simple cell structure, their 

 physiological functions are directly opposite. The first builds 

 up from simple to complex protein compounds ; the latter re- 

 duces complex compounds to simple ones, obtaining its protein 

 matters from higher organisms. 



Protococcus in sunlight decomposes carbon di-oxide, utilizes 

 the carbon in its structure, and sets part of the oxygen free, as do 

 the higher plants. Torula, on the other hand, absorbs oxygen and 

 throws off carbon di-oxide. Protococcus viridis is filled with 

 chloro-plastids, their absence in Torula enables us to distinguish 

 between them at a glance. 



All the complex plants have cells of the same physiological 

 features as e\\hQX Protococcus or Torula, which fact divides them 

 into two groups, first, those like the Protococcus, which give the 

 beautiful verdure to the landscape, while the fungi represent the 

 latter. 



As humble as our plant may seem from its classification, mod- 

 ern science is still unable to solve its mysteries ; it is one of the 

 great manufacturing chemists, among plants, converting crude 

 materials into combinations which, upon decay, may be taken up 

 by higher vegetation. Spread out upon trees and rocks, its 

 gelatinous substance is ready to catch and imbed the floating 

 dust and inorganic matter brought to it by the wind, some of 

 which will be converted and used. The air also brings great 

 carboys of carbon di-oxide and exchanges them for oxygen. 

 Fumes of sulphuric, sulphurous, nitric and nitrous acids, and 

 also ammonia come to be combined ; the rain brings chlorides 

 and other chemicals to be utilized. Each of the individual 



