ORGANISM AND MECHANISM 129 



self after the building materials of its edifice have been 

 artificially disarranged, of re-adjusting itself after the 

 proportions have been artificially disturbed. A fertilised 

 egg-cell frequently divides into a ball of cells like a micro- 

 scopic mulberry fruit; the constituents of this ball may be 

 disarranged and the ball pressed out of shape between two 

 glass plates ; yet if the interference be not too prolonged, 

 the developing embryo may right itself and develop nor- 

 mally. Can we think of a machine which is practically unaf- 

 fected if we cut off half of it, or which, being scrapped, 

 patiently re-arranges its parts and begins over again ! 



If the developing organism is in its behaviour ' cona- 

 tional '- — that is to say, on the way to being ' purposeful ' — 

 the difference between it and a developing sidereal system is 

 great. But what grain of evidence is there of this ^ cona- 

 tional ' element ? Not perhaps very much when we confine 

 our attention to normal embryonic stages, where one phase 

 appears to be the natural and necessary outcome of its ante- 

 cedent. But we get another impression when we consider 

 some of Driesch's cases of self-regulation and of re-adjust- 

 ment after profound dislocation. 



Whatever we make of it, one of the marvels of devel- 

 opment is the manner in which separate parts are often 

 correlated, as it were conspiring together towards some fu- 

 ture result. In the making of the Vertebrate eye, an outgrowth 

 from the brain forms the retinal cup, an independent in- 

 growth from the skin forms the lens, some mesoderm cells 

 migrate into the interior to form the vitreous humour, others 

 combine to form the protective envelopes, and so on. Strange 

 anticipations of coming events are well known to embry- 



ologists. 



In a trivial detail, such as the making of the silk-like 



