84 LECTURES ON BIOLOGY 



The attempt has often been made to explain the nucleus- 

 division mechanically. Comparisons have been instituted be- 

 tween the nuclear ' spindle-figures ' and magnetic force-lines ; it 

 has been possible to produce similar figures artificially in gela- 

 tine, &c., but no success has ever been recorded in passing in 

 such attempts beyond superficial analogies. We must agree with 

 Yves Delage who says that " it would be as futile to regard the 

 Lion, Balance and Fishes in the zodiac as a real lion, a real balance 

 and real fishes, as to regard mechanically formed cell-structures 

 and nucleus-division forms as real cell-structures and real nuclei- 

 division forms." We must, therefore, for the present be content 

 with a simple description of the processes, in the hope that 

 the restless research of later times may lead us to a deeper 

 understanding. 



