334 The Botanical Gazette. [September 
top of the culture dish with an opaque screen the light is ad- 
mitted only through the sides of the dish, and the object is 
thus photographed by reflected, instead of transmitted light. 
In this way very clear and minute details are obtained. Many 
fine photographs illustrating the method and its superiority to — 
the usual method were shown. ; 
The paper was discussed by Messrs. Galloway and Lasché. 
The author stated that he used Petri dishes, and that he con- 
sidered the method most serviceable in differentiation. 
2. G. F. ATKINSON: Symébzosz's in the roots of Ophioglos- 
se@.—In examining the roots of Botrychium Virginianum at- 
tention was called to masses of yellowish protoplasm located 
at definite points in the cortical parenchyma. From them 
threads extended tothe outside, branching profusely in connec 
tion with the masses. Examination of large sets of Botry- 
chium and Ophioglossum from all over the world revealed 
these structures in all. As root-hairs are not found in the 
Ophioglossezx, it was suggested that this fungus was of great 
service in the work of absorption, and that probably this habit 3 
prevails in all Ophioglossez. : 
Discussed by Messrs. Smith (Erwin F.) and Swingle. rs, 
3. B. T. GALLOWAY: Observations on a rust opens : 
leaves of the Fersey or scrub pine.—A full description 0 fe 
Trust (Coleosportum Pini) was given, and the course of its phe 
velopment, especially the conditions and time of its wee 
formations were fully described. Infection only takes se 
when the leaves are tender, from one-fourth to one inch oe 
and is usually confined to a period not exceeding two W rey 
In the discussion Professor Kellerman said that J piss : 
pine (Pinus Virginiana) was abundant in southern O He itch 
near Columbus southward, and was associated pia pas 4 
Pine (P. rigida). He had not found the fungus on en pine a 
Species in that state, but it was common upor the te q 
throughout the region. Professor MacMillan men pin ve 
unusual case of hypertrophy due to such a parasite, aad only 
in Minnesota, in which trees twenty to thirty bag . 
attained the height of a man, the whole tree becomins 
of witch’s broom. ctures 
4. W. J. BEAL: Prophylla of Gramince.—Thes* oe ith : 
were described, using corn and oats as exampie> ter, 159 
rac ' The ‘ 
: . : ; : a ‘ 
view to discovering their value as a diagnostic ae 
species belonging to fifty-six genera were - 
