BIOGRAPHICAL SKETCH OF JOHN ADAM RYDER. 677 



better for being a draughtsman; he should command a good literary 

 style; he should be a mathematician and physicist. Ryder, in these 

 preparatory years, attempted all these things but the last. His 

 endeavors to acquire new languages and a good literary style were 

 unending. One of his favorite pastimes was to read an essay of Addi- 

 son twice and then write out the essay from memory. He would then 

 compare his sketch with the original. His tastes in art were not 

 formed, and he rarely alluded to the subjects embraced among the 

 humanities. 



Mr. W. P. Seal, the well-known aquarium expert, was of great value 

 to Ryder at this time in bringing him all the unusual specimens he 

 detected while making collections of fresh water fishes and plants in 

 the neighborhood of Philadelphia. At the end of his service in the 

 Academy, Ryder had contributed thirty-one papers, most of which 

 were based upon studies made in the museum or on low forms of life. 



In 1880, the National Government was desirous of having investiga- 

 tions prosecuted in behalf of the United States Fish Commission on 

 the life history of the American food fishes and other aquatic animals, 

 especially their embryology and growth, the character of their food 

 in the early as well as the later stages of life. In the judgment of 

 Professor Baird, who was at that time Commissioner, no one in the 

 country possessed the qualifications to meet the provisions of such 

 investigations in so high a degree as Dr. Ryder. 



He was at once invited to undertake the work, which not only gave 

 him an opportunity of systematizing his studies (these were already 

 embracing the higher problems in biology), but had the advantage of 

 placing him in a better paid position. 



It is true that up to this date Ryder had given no special attention 

 to fishes, but he had obtained a general knowledge of the subject at 

 the academy; his inherited talent for invention lent itself readily to 

 the details of field work, while his acquaintance with the lower forms 

 of aquatic life fitted him for the study of the food of fishes, the study 

 of their young stages, their parasites, etc. 1 



Dr. Ryder always referred to this period with interest. His first 

 detail was to the field, but, in 1882, Professor Baird transferred him to 

 the National Museum, occasionally only assigning him to field work. 

 He was extraordinarily active during the six years he remained on the 

 Commission. He contributed twenty-nine papers on the oyster and 

 oyster culture, and fifty papers on the development of fishes, their 

 food material and methods of development. All his contributions 

 were carefully prepared and showed extensive knowledge of the sub- 

 jects treated. He discovered, in 1888, a byssus in a young stage of 



1 (1) The following papers, prior to 1880, related to Dr. Ryder's contribution to 

 ichthyology: "On the origin of bilateral symmetry and the numerous segments of 

 the soft rays of fishes ; " "Phosphorescence of very young llshes ; ; ' "The Psorosperms 

 found in Aphredoderus sayanus." 



