No. 375.] LOUIS AGASSIZ. 155 
away your fish and go home; perhaps you will be ready with a better 
answer in the morning. I will examine you before you look at the fish.” 
This was disconcerting. Not only must I think of my fish all night, 
studying, without the object before me, what this unknown but most visible 
feature might be, but also, without reviewing my new discoveries, I must 
give an exact account of them the next day... . 
The cordial greeting from the professor the next morning was reassuring. 
Here was a man who seemed to be quite as anxious as I that I should see 
for myself what he saw. 
“ Do you, perhaps, mean,” I asked, “ that the fish has symmetrical sides 
with paired organs?” 
His thoroughly pleased “Of course, of course!” repaid the wakeful 
hours of the previous night. After he had discoursed most happily and 
enthusiastically —as he always did — upon the importance of this point, I 
ventured to ask what I should do next. 
“ Oh, look at your fish !” he said, and left me again to my own devices. 
In a little more than an hour he returned, and heard my new catalogue. 
“ That is good, that is good,” he repeated; “ but that is not all; go on.” 
And so for three long days he placed that fish before my eyes, forbidding 
me to look at anything else or to use any artificial aid. “Look! look! 
look!” was his repeated injunction. 
This was the best entomological lesson I ever had,—a lesson whose 
influence has extended to the details of every subsequent study; a legacy 
that the professor has left to me, as he left it to many others, of inestimable 
value, which we could not buy, with which we cannot part. 
Agassiz did a great work by his teaching, but he reached a 
wider circle by his popular lectures delivered before lyceums, 
teachers’ associations, and farmers’ institutes, as well as by his 
writings. Considering the time of its publication, no better 
text-book has ever appeared than the Principles of Zoology by 
Agassiz and Gould, first issued in 1848. Of this work, which 
bears the impress of Agassiz on every page, only the first part 
was ever published, but this part has passed through many 
editions and has a sale even to-day. The second part was pre- 
pared by Dr. Gould; the manuscript was written out, many of 
the engravings made, but Agassiz never found time to revise 
it as he wished. Other popular works which extended the 
influence of Agassiz far and wide were his Methods of Study 
in Natural History, first published in the Atlantic Monthly, 
and his two series of Geological Sketches, most of which first 
appeared in the same periodical. 
