REACTIVATION OF EXTRACTED SPERM CELL MODELS 263 



As a result, for example, of what would seem to be the destruction 

 of normal permeability characteristics and ionic balance brought 

 about by extraction, the physiological properties involving coordina- 

 tion and intrinsic irritability of sperm models are lost. An acetyl- 

 choline-choline esterase system may also be destroyed (Tibbs, this 

 symposium). Coincident with these changes, two wave characteristics 

 are sacrificed: initiation at the base of the flagellum of the major uni- 

 planar wave, and its propagation toward the tip. The former property 

 suggests that normally some kind of stimulating mechanism, or pace- 

 maker, may reside at the flagellar root, in or near the basal granule 

 from which the axial filaments arise. This stimulus for wave formation 

 could conceivably originate in pulsed action potentials or potential 

 discharges, or be generated by rhythmic metabolic changes possibly 

 arising in, for example, the mitochondrial apparatus. Such a concept 

 of wave stimulation is not new (cf. Astbury et al., 1955; Bradfield, 

 1955), but the idea persists and is underscored by sperm model studies 

 which set this off as an event separate from wave formation per se. 

 The demonstration and elucidation of a stimulating and coordinating 

 system in sperm must depend on the skillful acquisition of precise 

 and pertinent data which may relate intracellular electrical changes 

 to activity during the flagellation cycle. 



The abolition of wave propagation in the models further implies 

 that a coordination mechanism is normally at work which involves 

 some kind of orderly transmission. Suggestions as to the basis for such 

 propagation have ranged from undesignated membranes and "con- 

 ductile" filaments (Bradfield, 1955; Inoue, 1959) to the contractile 

 elements themselves (Machin, 1958; Pautard, this symposium). The 

 failure of sperm models to propagate the active bending couples that 

 do occur suggests that there may very well be conductile character- 

 istics in normal flagella which are destroyed by extraction and perme- 

 ability changes (Bishop, 1958c). 



Judging from these flagellar models, the major or predominant 

 wave pattern — the only one found in extracted sperm — is two-dimen- 

 sional. The three-dimensional component which gives rise to helical 

 movement and which we believe is characteristic of motility of healthy 

 live sperm (Bishop, 1958c) is absent. This might be attributable to 

 the failure of wave propagation in the models. We feel, however, that 



