460 



form of the sperms seems so largely controlled by the nature of the 

 liquid to which they are exposed it is difficult to say whether we should 



regard the volute form Figure 5, or the 

 straight form Figure 6, as the more or 

 the less normal. 



An especially good demonstration of 

 the spiral arrangement of the arms in 

 unfolding may be had by restraining the 

 unfolding by strong KNO3 and studying 

 the sperms from side views. The arms 



Fig. 6. Unfolded sperm with straight arms: 

 seen from above. 



then tend to spring upward above the bowl in coils that retain the 

 diameter of the sperm instead of bending outward in loops: and thus 

 there are formed what at first seem to be rings piled up above the 

 sperm but which on careful focussing may be recognized as spiral coils 

 as indicated in Figure 7. Owing to the tenuity of the filaments of the 

 arms it is difficult to see them except on optical section but with 

 care they may be followed in spirals and counted. 



Their tips may be made out, approximately, and found to be at 

 different places; each arm is the same length as the others and both 

 begins and ends at a different part of the circumference of the imaginary 



cylinder about which we may 



conceive the arras as coiling. 



The above bowl-like cha- 



Fig. 7. Side view of sperm 

 uncoiling arms as spirals, in 20 "/o 

 KNO3. 



racter of the vesicle and the coiled arrangement of the arms may 

 be made out in preserved material after they have been seen in the 

 normal state. 



Successful results were got in material fixed in 2 7o osmic acid 

 and also in osmic fumes after the method of Herrmann; while 1 (.i 

 sections of testis and Vas deferens stained in Kleinenberg's haema- 

 toxylin or with Delafield and orange G and also others fixed with 

 alcoholic picro- sulphuric and stained with Conklin's stain enabled one 

 to demonstrate the same main facts. The arms, however, are most 

 always somewhat expanded and the differences between the sperms in 

 inner and outer parts of masses indicated that the fixatives diffusing 

 inward produce changes similar to those made by water in diluting 



