1887.] 1^5 [Claypole. 



means of seizing any one of them, of tracking it through space, of mark- 

 ing its course, of including the varjing effects of other globes, and finally, 

 from his complicated formula, he educes a prediction of its place at any 

 moment in the future. 



Is it too much to hope that some day the biologist too will rise to the 

 same position ; that some other and greater Darwin will be born to give 

 us a generalized law of variation ; that some biological Newton will arise 

 and enable us to compute the complicated problem which organic beings 

 present in passiog through their different stages of variation ? If even 

 now the pigeon-fancier will undertake to produce in a given time a bird 

 with any desired plumage (within possible limits) ; if the cattle-breeder 

 can call into being a variety retaining desirable and excluding undesirable 

 qualities ; if a gardener can develop a new and valuable variety of plant, 

 and fix its characters so that it comes true from seed for many years, why 

 should we not hope that some day the special will become the general, 

 and that what can now be done in a few cases will then be done in all at 

 will? When the effects of changes in the environment are definitely 

 known and traced back to their special causes, their direction and amount 

 determined and their condition so fully understood that they can be repro- 

 duced at pleasure, then will the material be in our hands for the final gen- 

 eralization. Is it too sanguine to hope that a biological analysis will then 

 be invented and perfected as mathematical analysis has been perfected, 

 and that the biologist, armed with this new engine of investigation, will 

 'be able to trace the past evolution of organisms to its causes in the organic 

 world? And, bolder still, may he not venture into the future, seize in the 

 grasp of his Calculus any variable organism, and involving in his formula 

 the successive conditions of its environment, trace it through its compli- 

 cated changes during its period of variance until his equation yields up 

 the function — the variate — at the end of any desired inj,erval, exhibiting 

 new characters and forming a new species ? 



Is such a prospect, though distant, altogether visionary ? May we not 

 hope some day to solve the great evolutionary problem ? Given, a vari- 

 able organism and the conditions of its environment during a certain time, 

 to determine the consequent changes. 



