An important event in the
development of nematology occurred in 1907, when N. A. Cobb joined the
U.S.Department of Agriculture.Cobb had secured his doctorate at Jena in
1889, after which he worked in Italy for a short time. Here he collected
nematodes, some of which hemounted in balsam; so expertly were the slides
made that the specimens are still in excellent condition. He then proceeded
to Australia, but failingto find professional employment he sold watches
until an opening was available in the New South Wales Department of Agriculture.
His firstpaper on plant parasitic nematodes, "Tylenchus and Root Galls,"
appeared in the Agricultural Gazette of New South Wales (1890). Apparently,at
that time he did not know that the names Heterodera and Meloidogyne had
already been proposed for the gall-forming nematodes
About 10 years later he
became associated with the Experiment Station of the Hawaiian Sugar Planters
Association, where he investigatedthe nematodes found in sugar cane fields.
Here he began developing equipment for microscopy, fitting the windows
with special shades andreflectors to control lighting while working over
the microscope and making camera lucida drawings. Much of this equipment
is still preserved atthe station.
His first assignment in
the U.S. Department of Agriculture was the standardization of cotton grades,
which were published in 1907. About1910 he succeeded in transferring his
attention to nematodes. His first paper, "New Nematode Genera Found Inhabiting
Fresh-water andNon-brackish Soils," was published in 1913. From that time
on, a long series of important papers came from his versatile pen. Among
his writingsContributions to a Science of Nematology is the most outstanding.
It was Cobb who proposed that plant parasitic and free-living nematodes
beremoved from helminthology and be assigned to a new branch of science
to be known as "nematology." He also proposed that "nema" besubstituted
for "nematode," and it is most unfortunate that this suggestion has not
met with general acceptance. His ingenious nature was thendirected to the
development of equipment and techniques necessary to separate nematodes
from soil and prepare them for microscopic study. Hislaboratory manual
"Estimating the Nema Population of Soil" (1918) formed the basis for a
large portion of the methods and apparatus used innematology today.
Studies on the minute morphological
details of plant parasitic nematodes occupied much of his time, with special
reference to those organswhich he named "amphids," "phasmids," and "deirids."
To secure a better perspective on their morphology, he studied the large
marine species, onwhich details were much more easily observed, and for
this purpose he spent several summers at the Bureau of Fisheries Station
at Woods Hole,Massachusetts. Those who were fortunate enough to be included
on these expeditions will ever remember those halcyon days of nematology.
Cobb's interests were not
confined to nematology and microscopy but extended to photography of birds
and insects and the development ofspecial equipment for photomicrography
and other microscopic work, , such as the installation of heavy pipes filled
with concrete to reducevibration during such work. Often these devices
resulted in weird and complicated assemblies, for he seemed to lack the
ability to simplify eitherapparatus or procedures. His laboratories were
always a show place of revolving tables with several microscopes on each
and special devices toperform laboratory techniques. Probably his most
useful invention was the metal microscopic slide, which many of us prefer
to the conventionalglass type. Another important contribution was the use
of a simple beam splitter and large mirror to replace the old-type camera
lucida.
His genial and humorous
nature will ever be remembered, especially by those who were present at
a certain meeting of the HelminthologicalSociety of Washington. He appeared
with numerous boxes and cartons which contained "A Collection of Holes,"
which he had assembled duringhis travels, and on them he proceeded to deliver
a solemn and profound dissertation which rocked the audience with laughter.
This was probablya satire on certain members of the society who always
had entirely too much to say about things of which they knew little or
nothing. His suddendeath at the age of seventy-three terminated all too
soon an important period in the development of the science of nematology.
No other individualhas had a more profound and permanent influence on the
profession than N. A. Cobb.
Associated with Cobb
during those early eventful years was W. E. Chambers, artist and microscopist.
From his gifted hands nematologyreceived the finest illustrations of nematodes
that have ever been made, and it is doubtful that they will ever again
be equaled. Cobb's microscopicability and unusual ingenuity, coupled with
the artistry of Ghambers, established a new era in nematology on which
our present science is largelyfounded, not only in America but in all parts
of the world. Among the early contemporaries of Cobb in the U.S. Department
of Agriculture wefind Ernst A. Bessey, soon after the turn of the century,
working on root-knot nematodes. His report (1911) included a review of
the principalwork done up to that time and included considerable original
research. This paper still remains one of the outstanding contributions
to ourinformation on this group.