244 F. 0. BOWER. 



tions. It is plain that whichever view be correct, the effect 

 upon our conception of the morphology of the cell and of its 

 contents would not be greatly affected : it is a question rather 

 of micro-chemistry and physics than of morphology. 



Thus far attention has been paid chiefly to the plastids 

 occurring in the tissues of the higher plants. Great advances, 

 however, have also been recently made in our knowledge of 

 the corresponding bodies in the lower organisms, especially 

 through the labours of Prof. Schmitz.^ 



He applies the terra chromatophore to all those definite 

 organs of the protoplasm which are coloured green, red, or 

 brown. All these bodies are morphologically analogous, and 

 only differ in their colour. 



At the outset the Cyanophycese (or Phycochromacese) are 

 excluded from consideration, on the ground that they, unlike 

 the other three divisions of Algse, have no clearly defined 

 chromotophores, or nuclei. He prefers to divide the Thallo- 

 phyta (excluding Myxomycetes) into three sections. 



1. Algae (including Chlorophycese, Phseophycese, and Eho- 

 dophyceae). 



2. Fungi. 



3. Schizophyta (including Schizomycetes and Phyco- 

 chromacese). 



In the Algae as above defined the chromatophores are always 

 definitely limited bodies, and the colouring matter is never 

 equally distributed throughout the protoplasm of the cell. 

 This statement is in direct opposition to the prevalent ideas; it 

 is usual to describe many green Algae as having uniformly 

 green coloured protoplasm, in which may or may not be em- 

 bedded chromatophores of definite form. Professor Schmitz, 

 however, asserts that, in the very large number of Algae which 

 he has investigated, all have chromatophores of definite form, 

 and he confidently extends that generalisation to all Algae. It 

 should be noted that Professor Schmitz recommends living 

 cells only as giving safe results; unhealthy material, or such 



' 'Die Cliromatopboren der Algen,' Yr. Schmitz, 1SS2. Bonn, Cohen and 

 Sohn. 



