BIOLOGY

life-lore; the description of all the phenomena of what is called life falls within its scope. For practical purposes, however, it is convenient to delimit this branch of science by excluding the study of human beings, except in so far as comparison and relation with other living organisms is concerned. Biology is, therefore, the comparative description of the structure, functions, distribution, and evolution of animals and plants, the more particular study of each being the function of the sciences _of Zoology and Botany respectively. gation of biological observations. A school of thought has arisen, in recent years, among biologists, which insists on the importance of quantitative measurements, especially in connection with observation regarding heredity and evolutionary proce es in general. In ‘the words of Profe or Karl Pearson, one of the leading exponents of the school, ‘biology requires the help of a more exact logic than it appears to po e , above all of an adequate statistical theory to enable it to interpret its observations and test its own theories.’ Bio metricists criticise much of the work of fellow biologists on the ground that they are too closely concerned with qualitative variations, while ignoring the quantitative aspect of the matter, thereby arriving at conclusions which can often be shown to be erroneous by a careful statistical study of the observations on which those conclusions are based. To illustrate this point by a simple instance, the statement that one race is characterized by long heads, and ‘am other by round heads is instantly challenged by the bio metricist, who insists upon numbers and percentages. To give another example, they point out that definite statistics regarding fertility are of supreme importance in examining the theory of the survival of the fittest, because the number of offspring of any particular type must affect the question of the perpetuation of that type, regardle of whether or not the characteristics of that type were such as to make it the best fitted to survive. Similarly, the study of correlation between death rate and environment, and between somatic characters and death-rate they claim to be vital to further progre in solving the problems of evolution, and such study can best be pursued along statistical lines. Their attitude has been much criticised by other biologists, who claim that they attach more meaning te their statistics than they can legitimately