36 THE PSYCHIC LIFE 



These little bodies, which in the vegetables are called 

 leucites, have a granular and reticulate structure; they 

 are impregnated with a coloring substance, at times 

 green, at times yellow, and at times brown, as the case 

 may be; in fact, several coloring substances are 

 present, which, by intermixture in different propor- 

 tions, form colors of many varieties. The best known, 

 after green chlorophyl, is yellow chlorophyl or diato- 

 min. The latter coloring substance can be absorbed 

 by alcohol. 



The Euglenoididae, the Chlamydomonadidae, and 

 the Volvocinae exhibit enormous chromatophores. In 

 the case of the Euglenae, the chromatophores are 

 formed of small discoid plates; they are situated di- 

 rectly under the cuticle, so that the light can act 

 upon them (see fig. 4). In certain species of Flagel- 

 lata, they are exhibited under the cuticle in the form 

 of two large plates which envelop the protoplasm 

 like a cuirass formed of two pieces. The Chlamydo- 

 monadidae and the Volvocinse have green chromato- 

 phores, disc-shaped, and very small. 



In the centre of the chromatophore a small bright 

 space is observed which was formerly thought to 

 be filled with chlorophyl; in reality, it is a minute solid 

 globule which shows an extremely close analogy with 

 the substance composing nuclei, or nuclein. It ex- 

 hibits the same chemical reactions; it actively absorbs 

 coloring matter and grows extremely brilliant when 

 treated with acids. Schmitz gives this little body the 

 name of pyrenoid (from TTI>P/> , nucleus). It is around 

 the pyrenoid, and probably through its action, that- 

 starch forms; it is deposited in grains or re-unites in a 

 ring about the pyrenoid, a fact easily ascertained by 

 coloring them with iodine. 



