BOTANICAL GAZETTE. 335 
ness of tissues, in the sense of the relation of water to other con- 
stituents, is the chief predisposing cause. . 
Mr. D. H. Campbell, whose paper appears in this number, in 
addition to his interesting anatomical study, is to be commended 
for pointing out the ease with which fern prothallia may be eul- 
tivated. These, too often considered material to be obtained 
with great difficulty, can be cultivated with no trouble. Sug- 
gestion was made that such culture afforded a good opportunity 
for experimenting upon the hybridization of ferns, 
__ Professor Coulter’s paper, published in this number, was more 
in the form of an annouhcement than a formal paper following 
eompleted work. It was readily agreed to by all, in the discus- 
sion that followed, that any attempted natural classification of 
Dicotyledons was better than the artificial one so long in use, and 
that organogeny might prove as successful in plant classification 
as embryology among animals. , 
Following Dr. Farlow’s paper, also published in this number, 
Mr. J.C. Arthur remarked that the hollyhock disease was one 
of great importance. It was ‘ntroduced into Europe in 1869, 
and aid Mr, C. B. Plowright has made various attempts to ae 
tunicate the disease to cotton plants, but without success. Re . 
- E. Bessey reported the same Puecinia, found by Dr. Farlow, 
on specimens of Malvastrum and Callirrhoe from Dakota. d 
. Sturtevant, in his observation on the hybridization an 
‘ross-fertilization of plants, used beans and corn as examples, 
also barley, peppers, squash, etc., and showed that where pure 
forms are crossed intermediate forms rarely occur. E 
rof. 
confirmed the 
siderable variation in percentage of duplicates ; ; 
f. Be 
