288 CONCLUSION 



in his laboratory, falls habitually into one or other of the known 

 crystalline systems. 



It seems, therefore, no more wonderful that the simple Mould 

 that develops de novo to-day should resemble another which 

 develops from the 'spore' of a pre-existing organism, than that 

 a crystal forming independently to-day in a saline solution 

 should resemble another which is capable of arising by the 

 growth of a fragment detached from a similar pre-existing crystal. 

 In all these cases, there is a similarity of product, because the 

 crystalline or organic form produced is to be regarded as the 

 physical expression of the harmonious actions which have led 

 to its production — because the forms are the results of a physical 

 necessity, and not of a mere blind chance.' 



What takes place in the reproductive processes occuri-ing among 

 higher forms of life seems to be only a more complex exemplifica- 

 tion of similar phenomena. As Herbert Spencer said,* " The 

 assumption to which we seem driven by the ensemble of the 

 evidence is, that sperm-cells and germ-cells are essentially nothing 

 more than vehicles in which are contained small groups of the 

 physiological units in a fit state for obeying their proclivity towards 

 the structural arrangement of the species they belong to. . . . 

 Thus, the phenomena of Heredity are seen to assimilate with other 

 phenomena. . . . We must conclude that the hkeness of any 

 organism to either parent is conveyed by the special tendencies 

 of the physiological units derived from that parent." 



Looked at in this general sense the phenomena of heredity seem 

 to be only special manifestations of the property we have spoken 

 of as ' organic polarity ' ; as a result of which, as we have seen, 

 parts of lower organisms are capable under suitable conditions 

 of reproducing similar entire organisms, just as a part of a crystal 

 immersed in its mother liquid will, when the conditions are 

 suitable, reproduce the form of the parent crystal. 



Neither Herbert Spencer nor Weismann alludes to the existence 

 of transformations in organisms at all comparable with the allo- 

 tropic and isomeric transformations that are so remarkable in 

 simpler forms of matter, and which, as is well known, increase 

 so much in frequency as the constitution of the matter becomes 



' Yet Prof. Huxley once made some very sensational remarks to a large 

 audience in opposition to such views (" Quart. Jrnl. of Micros. Science," Oct., 

 1870, p. 366). 



' " Principles of Biology," I, p. 317. 



