8 



Major and minor symmetries. 



Distinction between linear series and bilateral sym- 

 metry. 



Comparison with radial symmetry. 



Abnormal secondary symmetry. 



Kinds of Homology. 



1. General. 



a. Bilateral symmetry, homotypy. 



b. Serial homology, homodynamy. 

 r. Radial homology. 



2. Special homology. 



a. Complete. 



b. Incomplete. 



VI. THE ORIGIN OF THE INDIVIDUAL. 



i^Mo rpJiogciiesis. ) 



I. Abiogenesis vs. Biogenesis. 



(See Huxley, Spontaneous Generation, Lay Sermons, etc., p. 

 345, also Collected Essays, Vol. 8, pp. 229-271 ; CuEYNE, 

 Antiseptic Surgery, chapters 8 to 11.) 



Spontaneous generation generally accepted, Aris- 

 totle (384-321 B. c.) ; Helmont (1577-1644); 

 Harvey (i 578-1657) (Works, p. 427). 



Spontaneous generation of the higher animals dis- 

 proved, Redi (1 664- 1 690). 



Spontaneous generation advanced on philosophic 

 grounds, Buffon (i 707-1 788), and Needham. 



Experiments of Spallanz.ani, Sciiultze, Schwann, 

 SciiROEDER, and Dusch. 



Heterogenesis, Pouchet (1859). 



