420 H. M. KYLE [DECEMBER 



we see, can be divorced from the former, and in its making for accuracy- 

 is in truth but the expression of rationalised scepticism. Let us turn 

 to certain of the conclusions to which Heincke has been led by- 

 employing the theory. 



The variations that we find conforming to the laws of mathematics 

 cannot be considered as the " beginnings " or " makings " of new varieties 

 and species ; they are the actual condition of affairs, the product and 

 reflex of the varying elements of the environment. These variations 

 in structure are found to show the same appearance year after year, 

 and thus a similar curve of variations will be obtained year after year 

 although the individuals examined are of different generations. Similar 

 curves are obtained for different groups of the same species taken from 

 different regions although the mean or average value is changed. If 

 we look to the environment we see that the conditions there of tem- 

 perature, salinity, etc., present similar curves. We are surely entitled 

 to connect these two sets of variation and state that the one gives rise 

 directly to the other. 



The variations in organs which are of specific importance are for 

 the most part formed in the early stages of ontogeny when the organ- 

 ism is plastic and sensible to the fluctuations in the environment. 

 The range of variations is represented by the " variation coefficient," 

 the " probable error " of the variations. This is not exactly the same 

 for different regions, and hence forms a means of comparing the ranges 

 of the variations in the different environments. It also represents the 

 average capability of varying which each group possesses with regard 

 to the particular organ, whilst the total range of deviations actually 

 observed represents the variability for the group, and thence of the 

 species. The importance of the conception is evident. 



The individual as a combination of organs is, however, the turning- 

 point of the position of Heincke. Eeference might be made to eminent 

 biologists who have expressed similar ideas, but perhaps Herbert Spencer 

 comes the nearest. His conceptions of " life," the " balance of organs," 

 " direct and indirect equilibration," are almost exactly repeated by 

 Heincke in other words. But whereas Spencer took a broad view of the 

 problems of evolution, and thence showed the various factors in perhaps 

 their true perspective, Heincke has concentrated his attention on the 

 meaning of certain carefully observed facts. 



Each individual of a group is the chance combination ("permuta- 

 tion ") of a number of possibilities, each combination being equally prob- 

 able. Hence the individuals at the same stage of life, whether as 

 larvae, young, or adults, possess an equal " balance " of the possible varia- 

 tions of their organs. And similarly for other groups, the destruc- 

 tion that occurs is a destruction of combinations of equal value with 

 one another and with those that survive. The survivors give rise to 

 further combinations, each within the same range of variability as 

 before, and each equally probable, the exact combination and balance 



