EXPLOSION OF SPERMATOZOA OF LOPHOPANOPEUS BELLUS 



with sea water produces no change in the normal appearance 

 of the spermatozoa (Figs. 10 and u). An M/4 NaCl solution 

 brings about a slight shrinkage in the nuclear cup, otherwise 

 there is no further change. In an M/6 NaCl solution the second- 

 ary vesicle is very slowly everted. First of 'all it squeezes out 

 in the form of a small bubble (Fig. 12), until very gradually it 

 assumes the appearance shown in Fig. 13. In an M/y NaCl 

 solution the eversion of the secondary vesicle is much faster. 

 Figs. 14, 15 and 16 show successive stages in the eversion process. 

 Most of the spermatozoa proceed to the stage shown in Fig. 16 

 and then cease. An M/8 NaCl solution brings about a complete 

 and rapid explosion of all the spermatozoa. Figs. 17, 1 8 and 19 

 show respectively the beginning, middle and end of the process. 

 In Fig. 19 the secondary and primary vesicles, as well as the 

 central body are seen completely everted. 



3. Sodium Nitrate. An M/2 NaNO 3 solution which is isotonic 

 with sea water brings about no appreciable change in the normal 

 appearance of the spermatozoa. In an M/4 NaNO 3 solution 

 the only change noticed in the spermatozoa is a slight swelling 

 of the nuclear cup. An M/8 NaNO 3 solution causes a slow 



eversion of the secondary vesicle, producing figures similar to 

 those shown in Figs. 15 and 16. In an M/i6 NaNO 3 solution 

 the eversion of the two vesicles occurs rapidly and with con- 

 siderable force, so that all the spermatozoa soon take on the 

 appearance sho\vn in Fig. 19. 



4. Calcium Chloride. A 3/8M CaCl 2 solution is isotonic with 

 sea water and this brings about no change in the normal sperma- 

 tozoa. A 3/1 1 M CaCl 2 solution brings forth a partial eversion 

 of the secondary vesicle (Fig. 20). In a 3/i6M CaCl 2 solution 

 the spermatozoa explode completely. The vesicles are entirely 

 everted and at the same time the nuclear cup shrinks consider- 

 ably and becomes irregular. Figs. 21-24 show various stages 

 in the explosion process. In the CaCl 2 solutions the detailed 

 structure of the spermatozoa can be clearly distinguished. 



5. Potassium Chloride. In an M/2 KC1 solution w r hich is 

 isotonic with sea water the spermatozoa remain normal. In 

 M/4 and M/8 solutions of KC1 the only perceptible change 

 produced in the spermatozoa is a disappearance of the granules 



