-316 T. A. o'donohoe on the flea and blow-fly. 



Fig. 2. Shows the fine internal spiral in three of the spermatozoa 

 of the flea, x 1500. 

 ,, 3, The large form of the spermatozoon of the blow-fly 

 showing the three filaments of \vhich it is com- 

 posed, X 900. 

 4. In the centre is seen the head of a spermatozoon of a 

 flea, X 900. 



Journ. Quekett Microscopical Club, Ser. 2, Vol. XI., No. 69, Novendter 1911. 



