8 
Current Literature. 
NOTES ON CURRENT LITERATURE. 
The Proteolytic Ferment of Nepenthes. 
I N the December number of the “ Annals of Botany,” Professor 
Vines of Oxford criticises Clautriau’s work on the proteolytic 
ferment of the pitchers of Nepenthes , and restates his previous 
conclusion that the enzyme in question (Nepenthin) is tryptic rather 
than peptic in nature though it differs from trypsin in being active 
only in an acid medium, and apparently also in forming less leucin 
and tyrosin (which have not indeed been demonstrated at all). 
The ferments of the Papaw and the Pine Apple are intermediate 
in character between nepenthin and trypsin in both these respects, 
i.e., they are most active in neutral media and produce demonstrable 
leucin and tyrosin, though less than does trypsin. Professor Vines 
concludes with the interesting suggestion that tryptic digestion 
(which occurs alone in many invertebrates and is the only 
demonstrated proteolytic process in plants) is a property of all living 
organisms and the more primitive form of the digestive process. 
Anatomy of Gleicheniace^e. 
In the same number of the “Annals” M\ Boodle concludes 
his account of the comparative anatomy of the Hymenophyllaceae, 
Schizasaceae and Gleicheniaceae with a paper on the last-named 
family. The most interesting new fact is the discovery that one 
species (G. pectinata) is solenostelic, i.e. monostelic with a hollow 
cylinder of xylem clothed within and without by phloem, pericycle 
and endodermis, and enclosing a central pith. This affords clinching 
proof, if such is still needed, that this type of structure, which was 
called by Van Tieghem “ gamostelic ” and supposed to be derived 
from the “ dialystelic ” condition characteristic of the higher 
Leptosporangiate Ferns by lateral fusion of the separate “steles,” 
is (in this case at least) to be derived from the protostelic condition 
(monostelic with solid central xylem surrounded by phloem, pericycle 
and endodermis), which is almost certainly primitive in Gleichenia , 
by the development of internal phloem, etc. and central pith. 
The various other interesting points which Mr. Boodle works 
out, particularly the facts connected with the curious “ nodal 
