^,- ADVERTISEMENT. 



the young of the sponge has been proved to be like the phxniUu of a radiate, and 

 made up of two layers of cells. 



The last paper he published was entitled, ' Tlie American Spongilla, a Craspe- 

 dote, Flagellate Infiisorian,' in which he criticizes Haeckel's views on the affinities 

 of these animals, and insists upon their affinities to known Flagellate Infusoria 

 Tliis was published in December, 1871, in the American Journal of Science and 

 Arts. 



Busy with his work at Amherst, and struggling with the fatal disease (tabes 

 mesenterica) which was rapidly reducing his bodily strength, he wasted away, and 

 died on the first day of July, 1873, in full possession of his mental faculties. He 

 left a wife, seven surviving children, and many warm friends to mourn his loss. 



He was a man of the warmest sympathies, a devoted and affectionate husband, 

 a loving brother, and dutiful son; in many respects an admirable teacher, as a 

 lecturer clear and systematic, with an enthusiasm that evinced the true naturalist. 

 The secret of his success as an investigator may be stated in his own words taken 

 from his diary, where he says he made it a rule to practise the ' utmost rigidity 

 and thoroughness in his researches, without regard to time consumed or the value 

 of the results.' He had the best of teachers, and he made the most of his oppor- 

 tunities. We may look upon the results of his work as elevating the standard of 

 American scientific work. 



He was a member of most of the learned societies in this country, while his 

 works have been recognized and referred to by some of the leading zoologists in 

 Europe." 



JOSEPH HENRY, 



Secretary Smithsonian Institution. 



WASinN(iTo\, D. C, April, 1878. 



