44 MISSOURI BOTANICAL GARDEN. 
Abies balsamea, Pinus Strobus, Thuja occidentalis, Fraxi- 
nus nigra and Fagus Americana from Michigan; Pinus 
Taeda and Quercus rubra from Mississippi; Acer saccha- 
vinum, Cercis Canadensis, Pinus echinata, Cornus jlor- 
ida, Carpinus Caroliniana and Platanus occidentalis 
from Missouri; -Juglans cinerea, Juglans nigra, Quercus 
Prinus, Ulmus Americana, Pinus divaricata and Hicoria 
ovata from New Jersey; Tsuga Canadensis, Picea 
rubens and Liriodendron Tulipifera from New York; 
Tsuga heterophylla from Oregon; Juniperus Virginiana 
and Nyssa aquatica from Tennessee; Pinus palustris, 
Ilex opaca, Magnolia glauca and Quercus Phellos from 
Texas; Acer Pennsylvanicum, Acer rubrum, Prunus se- 
rotina, Betula lutea, Acer Saccharum, Ostrya Virginiana 
and Salix sp. from Vermont; and Libocedrus decurrens 
from Washington. 
Attention should be given to the fact that much of the 
material used by Potter in his work was taken from 
branches and not from the main stems of the trees. 
Whether there is any difference between the branches and 
the stem with respect to the amount of unlignified cellulose 
present is as yet not definitely known; but the possbility 
of such a difference should be kept in mind. 
CELLULOSE TESTS. 
The examination for cellulose was at first performed 
simply with the microscopic sections after they were cut 
ready for use, but it was soon perceived that this method 
would not give accurate results. The samples of wood 
were then very carefully examined in all parts. If no 
cellulose was then found another search was made to make 
sure that it had not been overlooked at first. Thus the 
specimens which had no cellulose were really subjected to 
a much more rigid examination than were those which 
proved to have it. 
