128 T O R R E Y A 



ings and for the support of adequate means of record and publication of their 

 discoveries. 



The simplest type of scientific activity is the naming and classification of 

 natural objects, and the first taxonomist of whom we have record was Adam, 

 who, according to the Biblical account, had all the plants and animals of the 

 Garden of Eden brought before him to receive their names. How natural that 

 the reawakening of human intelligence in the Renaissance should have been 

 characterized by the rise of taxonomy, the "mother" of all the biological 

 sciences ! A very substantial contribution to the unification of the biological 

 sciences was the adoption of the binomial system of nomenclature and its very 

 extensive applications to both plants and animals by Carl Linne in the middle 

 of the 18th century. 



The more philosophical phases of classification which came to recognize 

 natural relationships between genera, between families, and between groups 

 of still higher order developed more gradually and at the hands of an ever 

 increasing number of workers, both zoologists and botanists. On both sides 

 it was soon recognized that in one important corner of the taxonomic field 

 plant taxonomy and animal taxonomy overlap each other, so that Euglena, the 

 Myxomycetes alias Mycetozoa, and the Volvocineae, for example, have been 

 equally claimed by both plant and animal taxonomists. 



Another discovery of the greatest importance for the unification of biolog- 

 ical science was the recognition, independently and then jointly arrived at by 

 Schleiden and Schwann in 1839, that both plant and animal bodies are made 

 up of cells and substances and structures secreted by cells. This great gen- 

 eralization grew rapidly in importance as refined microscopical technique 

 brought to light ever finer details of intra-cellular organization without finding 

 a single consistent difference between plant and animal cells, either in the 

 structures they contain or in their physiological activities. 



These discoveries gave rise to the concept of biology as a single discipline, 

 especially through the writings and teachings of Thomas Huxley, Herbert 

 Spencer, John Tyndall and others. These writers emphasized the many com- 

 mon features of plants and animals, which made possible the stratification of 

 biological knowledge in fields at right angles to the taxonomic line of division 

 between the two Kingdoms ; thus tying them together by bonds more natural 

 than the divisions themselves between the Kingdoms. The principles of or- 

 ganography, tissue-dift'erentiations, competition and cooperation of parts, 

 specialization of tissues and the accompanying division of labor are equally 

 applicable to and derivable from plants and animals, as are all the fundamental 

 physiological processes, like nutrition, assimilation, growth, respiration, ex- 

 cretion and reproduction. 



With the development of the evolution hypothesis in the first half of the last 

 century and its gradual acceptance by all biologists, the fact that so many 



