1910.] NATURAL SCIENCES OF PHILADELPHIA. 259 



which position he retained until 1869, when he went to Europe for a 

 three years' course of study under Sir Richard Owen in London, 

 Alphonse Milne Edward in Paris, Emile DuBois Reymond in Berlin, 

 and Joseph Hyrtl in Vienna. 



His beloved friends Leidy and Conrad being his sponsors, he had 

 been elected a member of the Academy in 1868. For Dr. Leidy, espec- 

 ially, he entertained the most affectionate regard and he never lost 

 an opportunity of acknowledging with impulsive generosity his 

 indebtedness to the great naturalist for inspiration and encourage- 

 ment. His championship of his friend, who never answered criticisms 

 or decried injustice, was amusingly illustrated by a note to the American 

 Naturalist in which he calls attention to the fact that Wyville Thomson, 

 in his remarks on sponges, had neglected to state that Leidy was first 

 to correctly describe the natural position of Hyaloncma, Euplectella and 

 Pleuronema, concluding with the remark: "We trust that Prof. 

 Thomson will now gracefully throw up the sponge." 



Immediately on his return from Europe he applied himself to the 

 problems of evolution, in which he was deeply interested. The 

 result of his reading, for the most part in the library of the Academy, 

 was the publication of his first work, a volume of 193 pages entitled 

 The Evolution of Life. It was issued from the press September 17, 

 1872, although the title page is dated the following year. 



So assiduously had he devoted himself to the preparation of the 

 work that his health broke down and he was compelled to go abroad 

 immediately after placing the manuscript in the hands of his pub- 

 lishers, the preface being prepared in Paris. The proofs were corrected 

 and the index prepared by the Librarian of the Academy to whom 

 he had entrusted the pleasant duty of seeing the book through the 

 press. 



The introduction is an interesting resume of the history of the 

 doctrine of evolution. He acknowledges his special indebtedness 

 to Prof. Hyrtl, Dr. Friedlowsky, Dr. Klein of Vienna, Prof. Owen, 

 Mr. Flower of London, Prof. Gervais of Paris, and to his friends Drs. 

 Leidy and James Aitkin Meigs, for encouragement and advice during 

 the progress of the work. 



Although the book gives evidence of extensive reading, it is believed 

 that Dr. Chapman regretted later that he had not waited until 

 his judgment was more mature. The work, in common with nearly 

 everything published by the author subsequently, was written liter- 

 ally currente calamo and showed evidences of impatience of the 

 restraints of composition, punctuation, especially, being regarded 



