eighth year of his age. He was a member of most of the learned 

 societies in this country, while his works have been recognized and 

 referred to by the leading zoologists of Europe. 



In 1856 he was elected a fellow of the American Academy of 

 Arts and Sciences, and in 1870, an associate fellow of the same. 

 In 1857 he became a member of the Boston Society of Natural 

 History. In 1865 he was chosen a corresponding member of the 

 American Microscopical Society ; in 1866, corresponding member 

 of the Essex Institute, and in 1868, correspondent of the Phila- 

 delphia Academy of Natural Sciences. In 1872 he was elected a 

 member of the National Academy of Sciences, which, at that time, 

 was limited in membership to fifty of the foremost scientists of the 

 country. 



He married, 29th September, 1854, at Boston, Mary Young 

 Holbrook. Seven of their eight children are living, one daughter 

 having died in infancy. 



Mr. Clark's first love for science seems to have grown from his 

 fondness for flowers. After he became a student of zoology his 

 love for botany remained undiminished. "The influence of his 

 knowledge of botany on his zoological studies was marked. It 

 prepared him for his studies on spontaneous generation, on the 

 theory of the cell, on the structure of the Protozoa and the nature 

 of protoplasm. In the use of the microscope he showed not only 

 mechanical skill and ingenuity, but a patience, caution, and expe- 

 rience in difficult points in histology, which undoubtedly placed 

 him at the head of observers in this country, and rendered him, 

 perhaps, inferior to few in Europe. He used the highest powers 

 with a skill that few if any living observers have surpassed. His 

 work entitled 'Mind in Nature' is, in all respects, for its usually 

 souud and clear thinking, its breadth of view, and the amount of 

 original work it contains, perhaps the most remarkable general 

 zoological work as yet produced in this country. If the author 

 had left us no other work, this alone would testify to years of the 

 severest labor and independent thought. It anticipated certain 

 points in histology, and the structure of the Protozoa and Sponges 

 especially, which have made the succeeding labors of some Euro- 

 pean observers notable." Dr. A. S. Packard, Jr., in a Memoir 

 read before the National Academy of Sciences, in 1874, speaks of 

 Mr. Clark as follows: "Within the year past we have lost a 

 member who may be said, without disparagement to others labor- 



