SYNOPSIS 385 



PAGE 



/'. Complexity attained by differentiation of cell-wall or by forma- 

 tion of skeletal structures in the protoplasm. 



15. Foraminifera. 



Calcareous shells (cell-walls) of various and complicated 

 form 146 



1 6. Radiolaria. 



Membranous perforated shell (cell-wall) and external 

 silicious skeleton often of great complexity : symbiotic 

 relations with Zooxanthella ... 150 



1 7. Diatoms. 



Silicious, two-valved, highly-ornamented shells . . 153 



c. Complexity attained by simple elongation and branching of the 

 cell. 



1 8. Miicor 



A branched filamentous fungus : necessity for special 

 reproductive organs in such an organism : they may be 

 sporangia producing asexual spores, or equal and similar 

 gametes producing a resting zygote 156 



1 9. I 'aucheria. 



A branched filamentous alga : clear distinction between 

 the gametes or conjugating bodies and the sexual repro- 

 ductive organs or gonads in which they are produced : 

 gonads differentiated into male (spermary) and female 

 (ovary) : gametes differentiated into male (sperm) and 

 female (ovum) : zygote and oosperm ... . . 167 



20. Caulerpa. 



Illustrates maximum differentiation of a unicellular plant : 

 stem-like, leaf-like, and root-like parts . ... 173 



III. ORGANISMS IN WHICH COMPLEXITY is ATTAINED BY CELL- 

 MULTIPLICATION, ACCOMPANIED BY NO OR BUT LITTLE CELL- 

 DlFFERENTIATION. 



a. Linear aggregates. 



21. Penicillinm. 



A multicellular, filamentous, branched fungus : mycelial, 

 submerged, and aerial hyphre : apical growth : abundant 

 production of spores by constriction of aerial hyphre . 182 



22. Agaricus. 



Complexity attained by interweaving of hyphoe in a de- 

 finite form : illustrates maximum complexity of a linear 

 aggregate 189 



C C 



