SYNOPSIS 479 



PAGE 



14. Zoothamnium. 



A compound organism or colony with dimorphic (nutri- 

 tive and reproductive) zooids : begins life as a single 

 zooid 134 



b. Complexity attained by differentiation of cell-wall or by forma- 



tion of skeletal structures in the protoplasm. 



1 5 . Foraminifera. 



Calcareous shells (cell-walls) of various and complicated 

 form 148 



1 6. Radiolaria. 



Membranous perforated shell (cell-wall) and external 

 silicious skeleton often of great complexity : symbiotic 

 relations with Zooxanthella 152 



17. Diatoms. 



Silicious, two-valved, highly-ornamented shells .... 155 



c. Complexity attained by simple elongation and branching of the 



cell. 



1 8. Mucor. 



A branching filamentous non-cellular 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 158 



19. Vaucheria. 



A branched filamentous non-cellular alga : clear distinc- 

 tion between the gametes or conjugating bodies and the 

 sexual reproductive 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 an oosperm .... 169 



.:o. Caulerpa. 



Illustrates maximum differentiation of a non-cellular 

 plant: stem-like, leaf-like, and root-like parts 174 



III. ORGANISMS IN WHICH COMPLEXITY is ATTAINED BY CELL- 

 MULTIPLICATION, ACCOMPANIED BY NO OR BUT LITTLE CELL- 

 DlFFERENTIATION. 



a. Linear aggregates. 

 21. Penicillium. 



A multicellular, filamentous, branched fungus : mycelial, 

 submerged, and aerial hyphse : apical growth : abundant 

 production of spores by constriction of aerial hyphae . . 184 



