1896] Fishes of North and Middle America 



urgent insistence. It involved great strain upon 

 my far-sighted eyes, already fatigued by earlier work 

 and naturally becoming more presbyopic with age. 



Moreover, I had only recently begun to wear 

 glasses which I should have put on some years 

 before, for it was not until about that time that 

 Dr. George M. Gould's persistent warnings in regard 

 to eyestrains first came to my attention. I was then 

 particularly impressed by his account of the phys- 

 ical disabilities of many scientific workers (notably 

 of Darwin and Huxley) arising from lack of ocular 

 adjustments. 



Seeing little prospect of completing the task, I 

 reluctantly proposed to publish merely the first 

 half of Volume I, that is, the soft-rayed fishes up 

 to and including the sea-horses. But Mr. Hopkins Good 

 now came to my assistance, furnishing means by helpers 

 which I could enlist the aid of Dr. Evermann as 

 joint author. At the same time, Erank Cramer, an 

 able graduate student, generously volunteered his 

 services, as did also Thoburn and Meek. The work 

 appeared in four volumes, the first in March, 1896, 

 the second and third in 1898, the fourth in 1900. 

 In it we gave descriptions of all the fishes known in 

 America north of the Isthmus 3127 species, ar- 

 ranged in 1077 genera and 224 families. 



Meanwhile, during the two years and more of the University 

 Government Suit, I gave lectures on educational extenswn 

 subjects in all the principal towns of the state, 

 largely with the view of making as many new friends 

 as possible for the University, against the critical 

 time approaching. One of my most successful 

 courses was that given in San Francisco on "The 

 Factors of Organic Evolution." These I set forth in 



