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 

 number of invertebrate groups, pelagic tunicates, mollusks, mol- 

 luscoidea, Crustacea, and hydromedusaB. 



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. Most of his drawings were in pen and 

 ink, the 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 



