Texas Journal of Microscopy - Texas Society for Microscopy

she worked on the seeds of zucchini (Curcubita pepo) finishing
her thesis in 980. Her study of the dormant (completely dry) seeds
of zucchini is unique. Most ultrastructural research on seeds was
(is) done with seeds that had been hydrated. A set of surprising
results came from this research in which the fixation was by osmium
vapor. For example, the cell walls of the dormant cells are
folded in regular arrays that help maintain wall structure during
the dormant period and allow for the imbibition of water and expansion
during germination. A uniquely interesting finding from
this research was a material that filled the intracellular spaces in
dry seeds. This material “falls out” of its position in specimens
when they are fractured. The material is flexible and apparently
gel-like in consistency. Through a series of excellent micrographs,
Mary Alice also showed exactly how the protein bodies of the
dry seed become protein vacuoles and then develop into vacuoles
during the germination process. Like me, Mary Alice’s first research
was on seeds. I have examined and re-examined her thesis
recently, and without doubt, it is equivalent of most Ph.D. dissertations
at UTA or in the other four institutions where I taught.
Unfortunately, at the time, because of pointless state government
interference, we were not authorized to offer a Ph.D. degree (See
Part II). Working out the methods with which to examine seeds in
their dormant condition was a bona fide forward step in the study
of seeds that can
be attributed to Dr.
Webb.
Following her
graduation, Mary
Alice moved to
North Carolina
where she worked
for Dr. J. David
Robertson at Duke
Medical Center.
Dr. Robertson, well
known for his studies
of membranes,
is perhaps generally
remembered
Figure 24. Sesame (Sesamum indicum)
seed. The surface of the seed is covered
with cells which produce crystals of CaOx.
Adapted from Webb and Arnott, 1982.
for developing the concept of the “unit membrane.” Through that
and other research he was responsible for the stimulating interest
in membrane structure. After spending a year in North Carolina
Mary Alice returned to Arlington.
During the next few years Mary Alice worked as my research
associate as we began to study calcium oxalate in plants once
again. By this time many technical changes in the fixation of
specimens for the TEM had occurred and the SEM was providing
views of plant cells unattainable a few years earlier. Most of our
joint research was on crystals of CaOx and the cells that produce
them. Our publication record indicates that we were most active
in 980- 983 and again in 990- 994 producing 38 joint citations.
Between those periods of activity, Mary Alice finished her Ph.D.
degree in Botany at the University of Wisconsin and became an
Assistant and then Associate Professor at Purdue University.
As my research associate, Mary Alice worked mostly on projects
related to calcium oxalate. At the time, I was an administrator
and had limited time for research (See Part II), so she did a lot
of the literature research. However, when it came to microscope
work, our working arrangement was, more or less, that of a friendly
contest; i.e. we each tried “to out do the other” with better and
better micrographs. Actually this was “good practice” since the
competition produced many excellent micrographs. By the 90’s it
was sometimes difficult to know who took which picture and we
still have “friendly arguments” about that topic. On her return to
Texas, Mary Alice and I began to study CaOx crystals in various
Figure 25. Mary Alice
Webb standing in the U. T.
Arlington Dean of Science
office reviewing a paper
destined for the journal
“Scanning Electron Microscopy.”
Typing of the
manuscript was and had to
be letter perfect. Photo by
H. J. Arnott, about 1980.
subjects but especially in seeds. Seeds were one of my special
interests from the “get-go” (See Part III). The seed research soon
produced a substantial paper dealing with crystals in a variety of
seeds (Plates 8, 9). Indirectly, this line of research resulted in the
long term investigation of raphides in the leaves of Vitis. From that
work, the raphides of grape leaf became a model for calcium oxalate
production in plants. See the “adventures in the vineyards” later.
When Mary Alice returned to UTA, my lab had several students
working on biocrystal systems. In addition to running the EM lab,
Linda Lopez was working on the air space system and calcium
oxalate in Eichhornia crassipes. Mary Lou Kelly, an interdisciplinary
M.S. student, was studying the CaOx druse development
in the leaves of Rosa multiflora (Plate 20). Mark Grimson (Fig.
22), a Master’s student, was working on the twin CaOx crystals of
Phaesolus vulgaris (bean) and on the development of CaOx crystal-sand
idioblasts in the tuber of Solanum tuberosum (potato)
(Plate 2 ). Chris Workman, an undergraduate, was helping me investigate
the planar druses of CaOx in the leaves of okra (Fig. 23).
In 982, I had three papers in succession in Scanning Electron
Microscopy. The first, “A survey of CaOx crystals and other
mineral inclusions in seeds” (Webb and Arnott, 982), provided
a review and added new information about crystal in seeds. That
paper produced a set of principles for understanding problems of
minerals (crystals) in seeds. It provided references to crystals in
8 families of seed plants and new information on 8 species. It
included many transmission and scanning electron micrographs.
It included the first micrographs of Vitis seed coat raphide idioblasts
and of grape endosperm crystals. Sesamum indicum seeds
remind me of the following anecdote. One night in the 70’s, I
happened to run into Dr. Larry Thurston (see part I) at Los Angeles
Airport. We decided to have dinner in the Theme Building
Restaurant (that’s the large octopus-like building shown in advertisements
about LAX). As a part of dinner we were served some
small sesame seed crackers. A discussion came up as to where
you could find subject matter for SEM research. My position was
that you could find it anywhere. As a joke, I bet Larry that I could
publish a picture of a sesame seed from one of the crackers in a
scientific journal. I wrapped up a cracker in a paper napkin and
took it home and placed it in a small specimen box until work
on this seed paper came up. I kept the box with the sesame seed
cracker for some years (Fig. 24).
The second of the three papers (Grimson, Arnott and Webb,
982) deals with winged crystals in bean. The third paper, “Calcium
oxalate (weddellite) crystals in forest litter” (Arnott, 982)
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