i66 SCIENCE PROGRESS. 



determine the qualities of the animal or plant in which they 

 dwell. But any extended consideration of this topic would 

 open up the question as to the real permanence of the 

 chromosomes throughout the resting nucleus, in which they 

 can no longer be discerned, and would involve an exhaustive 

 discussion of the manner in which they emerge as distinct 

 bodies at each recurring mitosis. And even to touch on the 

 different questions and processes herein concerned would 

 occupy an entire morning. And I think I have already 

 taxed your patience severely enough without putting yet 

 more burdens upon it. 



I have tried in the foregoing account to point out how 

 widely opinions differ on the most fundamental questions, 

 the extremes being represented on the other hand by those 

 who see in all organised structures special organs of the 

 cell, which are permanent from generation to generation at 

 \e.a.sV mJ>osse, if not /// esse, and which in some way regulate 

 the changes which recur in cell life ; the other side, on the 

 contrary, regards the whole of cell phenomena, including 

 the very "Organs" themselves, as the outcome and ex- 

 pression of forces which have their origin in profound 

 chemical and physical changes as yet beyond our ken. But 

 just as the operation of the forces themselves is transient 

 il periodically recurrent, so also is the existence of some of 

 the so-called organs themselves. 



And perhaps in this, as in so many other matters, the 

 middle way is the safest, but I have not sought to follow it 

 because I did not consider it a suitable path for the purposes 

 of a discussion. 



" Serpit humi tutus nimium timidusque procellae." 



J. Bretland Farmer. 



