Phillips. — On a Common Vital Force. 617 



■cellular construction in trees, lime branches following designs 

 of which the polyp itself is supremely ignorant. It is the same 

 with the frost upon our window-panes, w^hich is often fern- 

 leaved in shape, so that it appears as if the vital force itself is 

 bound to follow certain fixed lines of construction, no matter 

 what the subsequent variations or divergences may be. This 

 implies that the force itself is subject to a higher law still. 

 With that implication I fully agree, for in many things, es- 

 pecially in construction, the force appears to act blindly. But 

 all I am at present called upon to do is to show the exemplifi- 

 cations of the force in different living things. I might perhaps 

 be allowed here to refer to the varieties of pigeons, if only to 

 show the maze Darwin found himself in when considering 

 their wonderful divergences. The rule of the law I am now 

 pointing out I think explains many of that great thinker's 

 doubts and hesitations.'" By admitting that no two things in 

 nature are exactly alike the potentiality of divergence is prac- 

 tically limitless. The peculiarity with pigeons, however, is 

 the wonderful and remarkable manner in which they differ and 

 divei'ge from the parent stock : as if in sport or play, nature 

 produces the carrier, the tumbler, the fantail, the pouter, the 

 Jacobin, &c., all from the rock-pigeon — a lavish wealth of 

 wondrous change giving us in this one species a perfect mine 

 of observation and experiment. "Who can define the limit of 

 these divergences, or even then- uses ? For of what use is it to 

 us here that soiiie types of the tumbler-pigeon cannot fly a 

 yard without tumbling head over heels ? Therefore it follows 

 that the theory of natural selection, failing in explaining these 

 pigeon divergences we already see, cannot account for the 

 potentiality of divergence yet to take place. In the few years 

 we have been experimenting we have surely not exhausted all 

 ihe mutations of pigeon form of life. It is therefore our duty 

 to search for the rule of life which governs future changes. 

 Darwin certainly lamentably failed to explain what he saw in 

 pigeon variation. 



The reason, I suppose, for these various divergences is, 

 of course, to enable species, order, or genera to adapt them- 

 selves to the changing conditions of climate and surroundings 

 in the different planets, geology showing us in this planet 

 that many varieties of one species are born, live for a time, 

 and die out, the species itself still going on, and existing in 

 a slightly different form. And this divergence is not only 

 necessary on account of the birth, growth, and death of the 

 planet itself, diiring which the various climatic changes occur, 

 but also on account of the alteration in other orders of living 

 things upon which the particular species depends. But this 



- * See " Origin of Species," cap. ii. 



