1914] CURRENT LITERATURE 253 
had Dr. Doorn had a longer experience with our ferns, and observed the great 
diversity of their form and growth, he would have realized that some of his 
new kinds were but growths of well known species.” 
Nearly 70 years of experience with plants in the field, much of it with 
Queensland plants, add to the weight of BAILEY’s comments. At the time of 
OMIN’S visit, the present reviewer was collecting morphological material in 
Queensland, and can heartily agree with the remarks regarding the variability 
of Psilotum, Marattia, and Platycerium. In Platycerium, particularly, the 
appearance of the plant is so affected by its position on the tree, that isolated 
plants might be described as new species, if the differences were not so obviously 
due, in some cases, to merely mechanical causes.—C. J. CHAMBERLAIN. 
A new seed genus.—Miss BENSON” has made Conostoma ovale Williamson 
the basis of a new form genus, which she calls Sphaerostoma. Along with 
C. ovale the doubtful species C. intermedium is included as S. ovale. In general 
structure the seed resembles Lagenostoma, and is found most frequently with- 
out its cupule (or outer integument), from which it doubtless separated when 
drop All of the epidermal cells of the integument are papillate, and at 
the apex, where the integument is free from the nucellus, they become so 
elongated as to form a whorl of epidermal crests, the ‘‘canopy”’ being 8-lobed. 
These crests Miss BENSON calls “‘frills.”’ 
The structure of the lagenostome, however, is quite peculiar. There is the 
usual central column of nucellar tissue, surrounded by the moatlike pollen 
chamber which is invested by the epidermis of the nucellus. But the roof of 
seed Pollen chamber is modified into what Miss BENSON regards as “an elas- 
tcally acting mechanism” which definitely closes the pollen chamber after 
there has been a dehiscence which admits*the pollen grains. This elastic 
mechanism, forming the roof of the pollen chamber, is the epidermis so modi- 
ed as to resemble in appearance a multiseriate annulus. The conclusion is 
at in dehiscence this mechanism straightens elastically, admits pollen grains, 
and then closes the chamber again. 
The seeds are provisionally referred to Heterangium Grievii on what seems 
‘0 be excellent evidence, namely constant association, suggestions of actual 
continuity of ovules with the parent plant, and the evident morphological 
relationship to Lagenostoma.—J. M. C. 
. 
; Culture of Opuntia.—Grirrirus* records some very interesting observa- 
Hons upon the behavior of certain species of Opuntia under culture. e 
Plants were grown at the government stations at Brownsville and San Antonio, 
eC ei eaee 
®” Benson, Marcaret J., Sphaerostoma ovale (Conostoma ovale et intermedium 
Williamson), a Lower Carboniferous ovule from Pettycur, Fifeshire, Scotland. Trans. 
Roy. Soc. Edinburgh so: 1-1 5. fies. 3. pls. I, 2. 1914- 
* GRIFFITHS, D., Behavior, under cultural conditions, of species of Cacti known 
4s Opuntia. U.S. Dept. Agr., Bur. Pl. Ind., Bull. no. 31. pp. 24. pls. 1-8. fig. I- 1913. 
