Modification of Germinal Conslilulion of Organisms 249 



combination is not known in nature, but there has twice 

 appeared in my cultures a somewhat similar variation which 

 could be classed as a sport, which variations, however 

 always failed to perpetuate themselves. 



These cultures are able to maintain themselves under the 

 conditions of the vivarium in both" group and pedigree 

 cultures without further attention, or attempts to main- 

 tain the race. More interesting, however, is the behavior 

 of these modified forms when placed in nature in their 

 normal habitat, where they have maintained themselves 

 with undiminished attributes, and there has not been the 

 slightest indication of reverting to the ancestral state. 

 When material of this type is crossed with material of the 

 parental stock obtained from the original locality, the 

 modified attribute behaves as a striking dominant alternative 

 characteristic. 



Of further interest is the ontogenetic series of events in 

 the development of this modified color pattern. In this 

 instance I know step by step exactly what went into the 

 combination, also what the ontogenetic sequence of events 

 was in each type of parent, and it is naturally expected that 

 the modifications would present a series of ontogenetic 

 stages one following the other, and that the ontogeny of 

 these modified individuals should rather closely recapitulate 

 the recent events which the organism has gone through in 

 attaining its present state. This is exactly what the organ- 

 ism does not do. Like any well-regulated physico-chemical 

 mechanism it cuts out the non-essential and takes the short- 

 est cut to attain its present end. This short cut, wherein 

 stages which it passes through in its ph}^logenetic develop- 

 ment are left out, and where many characters are lost com- 

 pletely, shows that in this instance a modified pattern has 



