THE BLUE ALG.E 



471 



passing to a more detailed examination of the higlier algas it 

 will be most instructive for us to study some of the simpler 

 forms. About as simple as any are the exceedingly minute 

 plants which for want of a better name we may call tint-ball 

 algas (Chroococcus), and which when highly magnified present 



Fig. 30.3. — Tint-ball Al^a (Chroococcus targiiias, Tint-ball I'aniily, C'h,rod(Oc- 

 cacecE). A, plant aa ordinarily seen; magnified about 400 diameters. 

 The inner shaded mass of protoplasm is bluish green, surrounded by a 

 transparent gelatinous envelope. B, same, beginning to divide into 

 two plants. C, the division advanced by the formation of a double 

 wall between. D, the division complete. (Rodraw^n from Kirchncr.) — 

 Found in wwamps and on wet rocks throughout the w-orld. 



the appearance shown in Fig. 30.5. An individual (A) consists 

 merely of a spheroidal mass of rather firm consistency and 

 Vjlue-green color, surrounded by a transparent gelatinous 

 envelope. Near the center of the mass may be seen under 

 favorable circumstances a comparatively small, somewhat 

 denser .spot. After the plant is dead, the application of pure 

 water dissolves out a blue substance — called phycoajanin ' — 

 leaving the yellow-green chlorophyll. This in turn if dis- 

 solved out by alcohol leaves a colorless, minutely granular 

 material which examined chemically would be found to 

 consist of a highly complicatetl mixture of proteids. To such 

 a mixture of (jrganized proteids the name protoplasm - has 

 been given. This when active forms the living part of the 

 plant. Whatever is alive in any plant or animal is protoplasm. 

 Hence protoplasm has been called "the jihysical basis of 



' Phyco-cy'an-in < Gr. phykos, seaweed; kyanos, blue. 

 '' Pro'to-plasm < ML. proloplasina. the first creature made < Gr. 

 protos, first; plasma, anything formed. 



