424 THE POPULAR SCIENCE MONTHLY 
In his treatment of assistants and collaborators he displayed a most 
commendably unselfish spirit, and indeed the only differences I experi- 
enced during eight years in which I served as his assistant were occa- 
sioned in persuading him to permit his name to appear as the senior 
author of publications which were actually the result of our joint efforts. 
Labor at the copper mines made enormous drains upon his seem- 
ingly inexhaustible energy, for during the early years of his connection 
with the company he worked upon an average of fourteen and a half 
hours each day. Yet arduous as these duties were between 1867 and 
1874 they made but little difference in the output of his scientific work, 
for in this period he produced 19 papers, one of them being his famous 
“ Revision of the Echini.” Another announces the discovery that 
Tornaria is undoubtedly the larva of Balanoglossus, and in another he 
proves that the peculiar pincer-like organs found upon the echini are in 
reality only highly: modified spines, and they serve to keep the animal 
clean by actually grasping and removing detritus from the surface of 
the creature. In another work of this period he presents a paper illus- 
trated by 202 excellent figures and giving a complete account of the 
embryology of those most diaphanous of marine animals, the 
Ctenophore. 
Indeed it may be said that while his later work was far more elab- 
orate and widely known, it was not more brilliant than that of this 
period which closed with his fortieth year, and these older papers are of 
such fundamental importance that they are quoted in all general text- 
books of zoology. We see then that these days of his early manhood 
between 1861 and 1873 were rich in achievement in science, and re- 
markable in other respects, for it was during this period that he raised 
himself from poverty to wealth more than sufficient to meet the demands 
of his expensive researches in zoology. 
But the “happy old days” were soon to pass away forever from the 
life of Alexander Agassiz, for on December 14, 1873, his great father 
died, and to deepen his misery his wife to whom he was devotedly 
attached passed away only eight days after his father’s death, and his 
own health, undermined by too strenuous labor, failed so seriously that 
throughout the remainder of his life he suffered from an impairment 
of the circulation which obliged him to seek a warm climate every 
winter. : 
Those who knew him in his happier years say that from this time 
onward a great change was observed in him. ‘These irreparable losses 
came upon him at a time when youth was gone, but middle age had 
hardly come upon him and most things of life were yet in store for him. 
Henceforth he was to live alone with his sorrow, master always of him- 
self, simple almost to austerity in his tastes, but deprived of that sym- 
pathy which only a wife could give, it is but little to be wondered at 
