i2o POPULAR SCIENCE MONTHLY. 



all organic nature. Observations were all moving towards a better 

 and more consistent conception of the structure of animals and plants. 

 A new comparative anatomy, more profound, and richer in meaning 

 than Cuviers, was arising. The edifice on the foundation of Von 

 Baer's work was now emerging into recognizable outlines. 



The Period of Balfour, with an Indication of Present Tendencies. 



The workers of this period inherited all the accumulations of pre- 

 vious efforts, and the time was ripe for a new step. Observations on 

 the development of different animals — vertebrates and invertebrates — 

 had accumulated in great number, but they were scattered through 

 technical periodicals, transactions of learned societies, monographs, etc., 

 and there was no compact science of embryology with definite outlines. 

 Balfour reviewed all this mass of information, digested it, and molded 

 it into an organized whole. The results were published in the form 

 of two volumes with the title of ' Comparative Embryology.' This 

 book of 'almost priceless value' was given to the world in 1880-81. 

 It was a colossal undertaking, but Balfour was a phenomenal worker. 

 Before his untimely death at the age of thirty-one, he had been able 

 to complete this work and to produce, besides, a large number of 

 technical researches. The period of Balfour is taken arbitrarily in 

 this paper, as beginning about 1874, when he published with Michael 

 Foster ' The Elements of Embryology.' 



Balfour was born in 1851. During his days of preparation for 

 the university he was a good student, but did not exhibit in any marked 

 way, the powers for which later he became distinguished. At Cam- 

 bridge, his distinguished teacher, now Sir Michael Foster, recognized 

 his great talents, and encouraged him to begin work in embryology. 

 After his work in this field was once begun, he threw himself into it 

 with great intensity. He rose rapidly to a professorship in Cambridge, 

 and so great was his enthusiasm and earnestness as a lecturer, that 

 in seven }^ears ' voluntary attendance on his classes advanced from ten 

 to ninety.' He was also a stimulator of research, and at the time of 

 his death there were twenty students engaged in his laboratory, on 

 problems of development. 



He was distinguished for personal attractiveness, and those who 

 met him were impressed with his great sincerity, as well as his per- 

 sonal charm. He was welcomed as an addition to the select group of 

 distinguished scientific men of England, and a great career was pre- 

 dicted for him. Huxley, when he felt the call, as a great personal 

 sacrifice, to lay aside the more rigorous pursuits of scientific research, 

 and to devote himself to molding science into the lives of the people, 

 said of Balfour: ' He is the only man who can carry out my work.' 



But that was not destined to be. The story of his tragic end 

 need be only referred to. After completing the prodigious labor on 



