290 NATHAN FASTEN. 



NORMAL APPEARANCE OF SPERMATOZOA. 



The living spermatozoa of Lophopanopeus bellus when studied 

 in the coelomic fluids of the crab are found to be small, greenish 

 bodies, which appear like spheroids when seen from the top or 

 bottom (Fig. i), and like ellipsoids when viewed from the side 

 (Fig. 2). In structure they seem to be similar to those of Cancer 

 magister. Within the centre there is a clear central body (Figs. 

 I and 2, b) and surrounding this are two vesicles; a uniform, 

 darkly green secondary vesicle (Figs. I and 2, v r ), and a clear, 

 transparent primary vesicle (Figs. I and 2,v). Outside of these 

 vesicles is a granular and vacuolated protoplasmic cup (Figs. I 

 and 2, /?) of a lighter greenish hue than the secondary vesicle. 

 If the spermatozoa remain suspended in the crab's body fluids 

 for some time their protoplasmic cups open up and liberate the 

 radial arms (Figs. 3-7). It is thus seen that the protoplasmic 

 cup of the spermatozoon consists of a nuclear cup (Fig. 3, n} and 

 radiating radial arms (Fig. 3, r). 



When the spermatozoa are fixed with osmic acid fumes and 

 stained by the iron-haematoxylin and acid-fuchsin methods, then 

 the nuclear cup, radial arms and the central body stain black 

 (see Figs. 3-7), the second vesicle stains a dark amber, whereas 

 the primary vesicle remains transparent. 



Four types of spermatozoa are produced, depending on their 

 number of rays. There is a three (Fig. 4), four (Fig. 5), five 

 (Fig. 6), and a six (Fig. 7) rayed type. The four (Fig. 5) and 

 five (Fig. 6) rayed types, however, are produced in largest num- 

 bers. These rays are not pseudopodia-like processes similar to 

 those which Binford ('13) pictures for the spermatozoa of Menippe 

 mercenaries. They are distinct arms similar to those found in 

 the crayfish Cambarus virilis and Cambarus immtmis, as pictured 

 by the writer in a previous paper on the spermatogenesis of these 

 forms (Fasten, 1914). 



EFFECTS OF CHEMICAL AGENTS ON SPERMATOZOA. 



1. Sea Water. Sea water produces no change in the normal 

 appearance of the spermatozoa. The protoplasmic cup, however, 

 swells slightly and liberates the radial arms (Figs. 8 and 9). 



2. Sodium Chloride. An M/2 NaCl solution which is isotonic 



