459 



teased in concentrated KNO5, dried on a cover glass and stained 

 with Delafield's haematoxylin, for the revolute stars may then be 

 brilliant orange-red while the spaces between the 

 arms, the bowl and a wide halo about the whole 

 is a dark, homogeneous blue. 



In a later stage the arms bend out from the 

 body as loops, since the tips either remain fast 



Fig. 3. Partly uncoiled sperm presenting a seven-armed 

 Swastika pattern : viewed from under side. 



later than the rest or else curl up over the top of the sperm so 

 that radiating loops are often seen as represented in Figure 4. Such 

 stages recall some of the attitudes of the fungus Geaster. 



The arms soon springing quite free and becoming more nearly 

 straight there results the familiar pin-wheel form so aften figured for 

 the European crayfish Astacus and represented for Cambarus in Fig. 5. 

 Though looking rigid the arms yield readily to pressure and may be 

 dragged behind when currents of liquid carry the sperm forward. The 

 number of arms in different sperms varies : it is often five (Figures 5, 



Fig. 4. 



Fiff. 5. 



Fig. 4. Partly unfolded sperm seen from above : the arms bent in loops. 



Fig. 5. Unfolded sperm with curved arms: a left-handed sperm seen from below. 



6, 7) or six (Figs. 2, 4) or seven (Fig. 3) and seems to be sometimes 

 four. The arrangement of the arms in relation to the axes of the 

 bowl seems to be indefinate and variable: though some sperms have 

 arms placed opposite the ends of the major axis of the elliptical bowl 

 and others arms placed symmetrically at the ends of minor axes, other 

 sperms have irregular relationships. 



Even greater extension of the arms may take place and result in 

 straight-armed sperms such as that represented in Figure 6. As the 



