598 Vines. —Proteolytic Enzymes in Plants (II). 
gar is), with Equisetum sp. (rhizome), and with the leaves 
and rhizomes of various Ferns, all gave negative results. 
Turning to the Phanerogams, the authors give first their 
results with laticiferous and resinous plants, and these are 
rather conflicting. They found no digestive action in the 
liquids of the various Fumariaceae ( Corydalis luted), Papaver- 
aceae ( Papaver somniferum, P. Rhoeas , Argemone mexicana ), 
and Compositae ( Crepis setosa , Sonchus tenerrimus , Taraxa- 
cum officinale, Lactuca sativa) that they investigated. On 
the other hand, positive results were obtained with all the 
Urticales tested, viz. Ficus Carica and F. elastica, Morus alba 
and tatarica , Broussonetia papyrifera, and Maclura aurantiaca. 
In the remaining orders, some species were, whilst others 
were not, found capable of liquefying the gelatine ; for instance, 
in the Euphorbiaceae, Euphorbia Lathyris, E. Tirucalli, E. 
canariensis, E . balsamifera, E. coerulescens , E. grandidens , 
and Poinsettia pulcherrima were active, whilst Euphorbia 
tigridis and dulcis, Homalanthus populifolius, and species of 
Croton were not : similarly in the Convolvulaceae, Cotivolvulus 
sylvaticus and Calonyction (Tpomoea) macrantholeucum were 
active, but not Convolvulus arvensis and species of Ipomoea : 
in the Asclepiadaceae, Tweedia neerifolia and Asclepias curas- 
savica were found to be active, but not Hoya carnosa : in the 
Apocynaceae, Tanghinia venenifera and Plumeria alba were 
active, but not Vinca minor, Acokanthera spectabilis, nor 
Echites flavescens. It is interesting to note that the resin of 
Pinus halepensis showed some activity, if only weak, as did 
also the secretion of Nelumbium speciosum. 
Of juices expressed from the plant, but few were active, 
namely those obtained from the young leaves of Agave 
mexicana and A. americana, from the young stems of Phyto- 
lacca dioica, from the stems of Anagallis arvensis, from the 
apices of the shoots of Glycine sinensis. Amongst the con- 
siderable number of inactive juices were those obtained from 
old leaves of Agave mexicana , and from adult branches of 
Phytolacca dioica ; hence it would appear that young tissues 
are more likely than old ones to contain the protease. 
