16 COMPENDIUM OF GENERAL BOTANY. 



Those organized plasmic masses which represent the fertilizing 

 elements in reproduction will be referred to in the chapter on Re- 

 production. Before passing to the consideration of the dead inclu- 

 sions of cytoplasm we will mention a few special plasmic structures 

 whose significance is, in part, not well understood. 



1. Cilia (Wimpern, flagella) of swarm-spores and spermatozoa 

 serve as organs of movement. Their number and manner of 

 attachment vary greatly (one or two, covering the body entirely, or 

 only partly). The cilia of spermatozoa originate in the cytoplasm ; 

 they are not nuclein. 



2. The so-called eye-spot (red or red-brown) in swarm-spores of 

 algae had already been noticed by earlier authors. Morphologically 

 it belongs to the chromatophores (KLEBS). It k said to be very 

 sensitive to mechanical pressure and to certain alkaloids. Its func- 

 tion is unknown. 



3. The iridescent plasmic plates in the superficial cells of various 

 marine algae probably serve to protect the chromatophores from 

 intense light (discovered by BEBTHOLD). 



4. In root-tubercles of Leguminosae there are constantly found 

 certain proteid bodies resembling bacteria, called bacteroids 1 

 (Brunchorst). They eventually serve the purpose of converting 

 nitrogen-bearing organic compounds into albuminoid substances. 



We will now turn our attention to the dead inclusions of 

 cytoplasm. 



B. DEAD INCLUSIONS OF CYTOPLASM. 



Dead inclusions as distinct from "plasmatic" inclusions play 

 only a passive role in plant chemistry. This, however, does not 

 make their physiological significance any less important. In the 

 discussion of many of these structures I shall adhere in general to 

 A. ZTMMERMANN'S a treatment of them : this also will hold true of 

 my treatment of the general morphology of the cell. 



In mass and importance starch-grains stand first. Almost 

 equal to them in importance but of less frequent occurrence are the 

 aleuron-grains (gluten), including the protein-crystalloids. To these 

 must be added fat-crystals, solid coloring substances, and mineral 

 excretions, especially in the form of crystals. 



1 These bacteroids are now generally admitted to be true bacteria belonging to 

 the Schizomycetes. Their development has been observed in culture media. Trans. 

 'Die Morph. und Phys. der Pflanzenzelle. Breslau, 1887. 



