158 BIOLOGY AND ITS MAKERS 
In 1827 he introduced into biology the fruitful idea of the divi- 
sion of physiological labor. He completed and published 
excellent researches upon the structure and development of 
many animals, notably crustacea, corals, etc. His work on 
comparative anatomy took the form of explanations of the 
activities of animals, or comparative physiology. His com- 
prehensive treatise Legons sur la Physiologie et P Anatomie 
Comparée, in fourteen volumes, 1857-1881, is a mine of 
information regarding comparative anatomy as well as the 
physiology of organisms. 
Lacaze-Duthiers.—Henri de Lacaze-Duthiers (1821- 
tgo1), the man of comprehensive mind, stimulating as an 
instructor of young men, inspiring other workers, and pro- 
ducing a large amount of original research on his own ac- 
count, director of the Seaside Stations at Roscoff and Banyuls, 
the founder of a noteworthy periodical of experimental zodl- 
ogy--this great man, whose portrait is shown in Fig. 44, was 
one of the leading comparative anatomists in France. 
R. Owen.—In Itngland Richard Owen (1804-1892) carried 
on the influence of Cuvier. At the age of twenty-seven he 
went to Paris and renewed acquaintance with the great Cuvier, 
whom he had met the previous year in England. He spent 
some time at the Jardin des Plantes examining the extensive 
collections in the museum. Although the idea was repudiated 
by Owen and some of his friends, it is not unlikely that the 
collections of fossil animals and the researches upon them 
which engaged Cuvier.et that time had great influence upon 
the subsequent studies of Owen. Although he never studied 
under Cuvier, in a sense he may be regarded as his disciple. 
Owen introduced into anatomy the important conceptions 
of analogy and homology, the former being a likeness based 
upon the use to which organs are put, as the wing of a butter- 
fly and the wing of a bat; while homology is a true relation- 
ship founded on likeness in structure and development, as 
