Spermatozoa. 91 



Take a large male newt which may be known by the 

 serrated crest or fin along the back, and kill it, quickly 

 remove the viscera, and the testes will be found, gen- 

 erally two or three each side, as small round bodies 

 which cannot easily be mistaken. Take one of these and 

 make a small cut in it, remove some of the milky fluid 

 which exudes to a slide, and add a little salt solution or 

 distilled water. Cover and examine. A power about 

 i will be required to see the spiral filament well. 



A large number of spermatozoa will be seen in the 

 field making slight lashing movements with the long 

 filiform body, and on closer examination the filament 

 will be seen in rapid movement ; this movement com- 

 mences at the elliptical body at the base of the head, 

 and gives the idea at first sight that the filament is 

 being poured out from it. After watching for some 

 little time, the movement will become slower, and it 

 can then be seen that the filament is attached to the 

 body by a membrane, and that it is waved rapidly 

 from side to side, by carefully watching it as the 

 motion gets slower and nearly stops the -membrane 

 connecting the filament to the body, can be clearly 

 seen. 



To MAKE A PERMANENT PREPARATION OF NEWT'S 

 SPERMATOZOA. 



Place the testes in 5 per cent, solution of chromate of 

 ammonia for 24 hours ; wash until no colour comes 

 away in distilled water, then divide one of the testeg 

 in two, and taking one half in a pair of forceps press 

 the cut surface on a glass slide, a small quantity of 



