112 PIERRE H. GONSE 



Z 0i of 0.9. In other preparations we observed Z values from 2 to 3, 

 within the range of 1.6 to 4.0 as reported by Humphrey (1950) for 

 oyster spermatozoa at the same dilution. The highest Z 0l values for 

 Spisula sperm would give a TN a of about 5 sec -1 , which is comparable 

 to a TN a = 4.8 shown in Table II for dog spermatozoa (Z 02 of 1 1.4). 

 Washed bull spermatozoa, in the presence of lactate had a Z 0l of about 

 3 in this study; values of 10 are reported elsewhere (Melrose and 

 Terner, 1953) which would correspond to a TN a of about 6. All three 

 spermatozoa thus have roughly identical turnover numbers for cyto- 

 chrome a. When calculated for cytochrome c, the turnover number is 

 about 15, well within the range of values found for other mammalian 

 tissues (Chance and Williams, 1955). In Spisula, however, the TN c 

 will be only 5 owing to the different proportion of cytochromes. By 

 and large these figures are very close, and one can conclude that the 

 respiratory chains in the three types of spermatozoa studied here 

 operate at similar rates and that these rates are within the range of 

 those of body tissues. 



For the purpose of comparison, the values of molarity per cell 

 (Table II) may not be very meaningful. Two other calculations 

 have been made in an attempt to express results in terms of intra- 

 mitochondrial molarity and number of molecules per cell (Table 

 III). The necessary assumptions concerning sizes of mitochondria 

 and middle piece are derived from figures and photographs given by 

 Galtsoff and Philpott (1960) for oyster spermatozoa, Randall and 

 Friedlaender (1950) for ram sperm, and Yasuzumi (1956) for rat 

 sperm. Despite the fact that our figures for mitochondrial dimensions 

 are the highest logically permitted, the values found for cytochrome 



Table III. Cytochrome concentration and number of molecules in the 

 spermatozoa of Spisula and bull 



Cytochrome a All Cyto- ^°' c{7 \n No - of MoIe " Volume of 



Sperm in M/10'i chromes in xV-. i, cules of All Mitochon- Assumptions 



Cells/1 M/10'i Cells/I Ml ™"' Cyt/Cell drion 



Spisula 32 X 10-9 M 136 X 10-9 M 3.02 mM 0.8 X 10« 0.45 M 3 4 spheres: 0.6 M 



dia. 



Bull 155 X 10-9 M 482 X 10"« M 0.73 mM 2.9 X 10 l 6.6 p* Sheath: 15 M 



long, 0.9 fi ext. 

 dia., 0.5 ii int. 

 dia. 



