A SKETCH OF HIS LIFE 
25 
PROFESSOR BROOKS AS AN INVESTIGATOR AND WRITER 
Professor Brooks' investigations lay mainly in the field of 
animal morphology and embryology. In this field he was an 
acute observer possessed of great patience and pertinacity. His 
philosophic insight and breadth of view, moreover, made him 
alert to the significance of what he observed, and his memoirs 
are hence notable for their suggestive and broad theoretical dis- 
cussions. Fundamental resemblances in the development and 
anatomy of forms were the phenomena in which he was especially 
interested. Interrelationships between groups and the phyloge- 
netic value of embryonic and larval characteristics were the specu- 
lative problems on which he brought his discoveries to bear. In 
reaching conclusions from facts he showed the caution of the 
observer who had seen much, and his soundness of judgment is 
widely recognized. Nevertheless he was at times not averse to 
bold speculation, as may be seen in his instructive discussion of 
the nature of the early pre-cambrian fauna, and the origin of the 
existing great groups of animals (The Genus Salpa and The 
Foundations of Zoology). His morphological studies embraced a 
niunber of invertebrate groups, pelagic tunicates, mollusks, mol- 
luscoidea, Crustacea, and hydromedusse. 
The illustrations in Brooks' memoirs are striking. It was his 
practice to make them himself, and they have the artistic excel- 
lence combined with truthfulness of detail found only in the work 
of the artist-naturalist. Alost of his drawings were in pen and 
ink, thfe shaded parts stippled, and made on a large scale suitable 
for reduction. They represented much labor, but Brooks was a 
quick worker in this style, which he preferred above all others. 
The mechanical process of stippling aided him, he maintained, to 
abstract his mind and to follow out lines of thought quite unrelated 
to the drawing. With respect to his artistic skill Brooks was with- 
out egotism, and when the drawings were once reproduced the 
originals were thrown away. 
Together with skill in drawing Professor Brooks was unusually 
fortunate in possessing literary power in a marked degree. His 
subject is presented in an order and manner that makes it easy 
