for Systematic Biology. 277 



method of work we are referring to will discover its true place 

 and receive new life and stimulus from the discovery. This 

 particular study does not deal with our series of units as series 

 but works within the individual unit, i.e. with its numberless 

 reproductions; and it may be that a mathematical study of the 

 fine quantitative variations among the representatives of a unit 

 may reveal to us the laws which link one unit with the next 

 above it and the next below it, or explain the divergence of a 

 unit into two or three new ones. We shall only know when we 

 can compare its results with those obtained by the comparative 

 method. I feel confident, indeed, that all along the line, biological 

 study will be both controlled and stimulated to new efforts, and to 

 new enquiries, as soon as our systematic work supplies us only with 

 facts, and facts arranged ready for further research. For instance, 

 as soon as we can leave the ' species ' to take care of themselves 

 and have forms as the main objects of systematic work, and 

 collect and arrange and study these, observing the surroundings 

 in which they are produced to get all the knowledge we can about 

 them and about the causes of their differences, we shall, it seems 

 to me, be laying the best foundations for the study of evolution 

 and of the laws and causes of variation. Without wishing to 

 make any rash prophecy, it really seems to me as if the change 

 of the unit of classification here advocated by confining the work 

 of the systematist strictly to the facts of Nature, would stimulate 

 Biology almost as much as it was stimulated a century and a 

 half ago by the original adoption of the Linnean system itself. 



But, leaving these ideal advantages to be gained by the system 

 advocated on one side, I only wish to emphasise the advance 

 which the science of systematic biology must make as soon as we 

 have a real instead of an ideal unit of classification. It is evident 

 that with a symbol for the designation of each varying form, all 

 our systematic work can, from its very first step to its last, be 

 made, relatively speaking, exact and, so far as it goes, constructive. 

 We shall be simply accumulating the facts out of which definitive 

 classifications can be slowly built up. We need establish no more 

 hypothetical ' species ' for the perplexing of the next student ; as 

 already stated the facts will themselves reveal the true species in 

 process of time. And then, but not till then, we shall be able 

 as far as I see to name such species in the usual way with the 

 Linnean binominal formula. 



It is, then, primarily to this demand for a change in the unit 

 of classification for the purposes of work that I wish specially to 

 draw attention. The question as to what symbol shall be used 

 for the new unit is quite a different one. I have described below 

 a system which, with the assistance of my friend Mr Jeffrey Bell, 

 I have already elaborated for the purpose of working out the 



