SPERM 91 



Gemmill (1900). Cohn (1918) found that increased alkalinity in- 

 creased the activity with a corresponding decrease in length of life; 

 and that increased CO 2 decreased activity and increased length of 

 life. In concentrated sperm, more CO2 is produced which inactivates 

 the sperm and they live longer. Increasing the temperature increases 

 the activity as one would expect. KCN inactivates them and prolongs 

 their Hfe (Cohn, 19 18). 



The motility of sperm is increased by egg water or egg extracts 

 (F. R. Lillie, 1913b, 1915a, 1919, p. m, etc.; Woodward, 1918; 

 Cohn, 191 8; Sampson, 1922; et al). According to Hartmann et al. 

 (1939), it is the echinochrome in the egg water of ^. lixula that causes 

 the activation. Tyler (1939), however, found this not to be true for 

 Strongylocentrotus purpuratus, and Cornman (1941) for A. punctulata. 



Other sperm-stimulating substances have been found by Clowes 

 and Bachman (1921), including propyl, allyl, and cinnamyl alcohol, 

 propylene, and a "volatile substance derived from marine eggs." 



The sperm of Arbacia are immobile when in the testes, and become 

 motile only when diluted. The sperm are immotile in absence of 

 oxygen and therefore cannot fertilize the eggs (E. B. Harvey, 1930); 

 they are also immotile in KCN (Cohn, 1 9 1 8) ; Loeb (1915a) had found 

 this for Strongylocentrotus purpuratus. Motility is also suppressed by halo- 

 and nitrophenols (Clowes, 1951) and by dilute HgClg (F, R. Lillie, 

 1921b), and by the SH reagent PCMB (p-chloro-mercuri-benzoate) 

 (Runnstrom, 1952). 



Sperm are more resistant to anaesthetics than are the eggs, but they 

 can be anaesthetized. In 0.2 M ethyl urethane they lose their fertiHzing 

 power in | hour and their motihty in 2 hours (E. B. H.). Chloretone 

 is efficacious in quieting them. 



In Ca-free sea water, the sperm are motile and surround the eggs 

 but will not fertilize them (E. B. H.; et al.); this was observed many 

 years ago by Loeb (1915a). 



d. Longevity 



Although there are many references in the literature to increasing the 

 life span of sperm, it would seem that the length of life depends on 

 their activity, and this is dependent on many factors as described 

 above, and especially on temperature. The less active they are, the 

 longer they live. However, Budington (1935) says that acetylsalicylic 

 acid (aspirin) causes sperm to retain their fertilizing power longer. 

 Tyler (1950, 1955) found that various amino acids and peptides, ver- 



