ON THE DEVELOPMENT OP THE SPERMATOZOA. 
79 
On the Development of the Spermatozoa. Part I. Lumbncus, 
By J. E. Bloompield, B*A. Oxon. With Plate YI. 
The investigation into the structure of the testis and the de- 
velopment of the spermatozoa, of which the present chapter on 
Lumbricus is an instalment^ was undertaken at the suggestion 
and with the kind supervision of Prof. Lankester, and has been 
carried out partly in the laboratory of Exeter College, Oxford, 
partly in the new zootomical laboratories at University College, 
London. 
The true testes of the earth-worm were first described by 
Hering (' Zeitschr. fiir wiss. Zool.,^ vol. viii), who did not, how- 
ever, figure them in position. They occupy much the same 
position in the tenth and eleventh rings of the body as do the 
ovaries in the thirteenth ; that is to say, they are placed in 
pairs in those rings well forward, so as to be in relation to the 
anterior septal wall and near the neural median line. Each 
testis is a pure white, translucent body, of irregularly quadran- 
gular form, rarely more than -pVth of an inch in diameter, 
much flattened, and attached by one side to the coelomic epithe- 
