324 BOTANICAL GAZETTE [MAY 
examination of Ricinus major and Vicia Faba. His experiments 
show that the proteids in the sprouting seeds of all these species 
will undergo autolysis, giving rise to products not precipitable by 
phosphotungstic acid. From L. /uteus he made a proteid prepara- 
tion by the Wittich method (solution in glycerin and precipitation 
by alcohol) which acted on “conglutin” with the formation of leucin 
and tyrosin, but not of asparagin. 
Vines"! found some difficulty in getting a formation of tryptophan 
in the autolysis of germinating seeds of Vicia Faba; the reaction 
was readily obtained, however, if Witte peptone was added to the 
mixture and digestion allowed to proceed. He found that the embryo 
of the wheat contains an enzyme which readily attacks Witte peptone 
and apparently has some slight action on some of the proteids of 
the embryo. 
As stated above, the first step in demonstrating that proteases 
are universally at work where proteids occur, is to show that all 
living plant tissues contain proteolytic enzymes. Investigations 
of this sort have been undertaken but recently. The older researches, 
which did not have this purpose, did tend to show that active pro- 
teases occur in places other than germinating seeds. The papain 
of the pawpaw fruit, the bromelin of the pineapple juice, the cradein . 
of the latex and juice of the fruit of the fig, and the protease of the 
Kachree gourd and of Anagallis arvensis have been known for some 
time, but these plants were looked upon as exceptional. 
Fermtand Buscationr? were the first to make a systematic examl- 
nation of a large number of plant tissues. Their method consisted 
in placing the objects to be tested on gelatin containing phenol as an 
antiseptic. If the gelatin was liquefied by the tissue or tissue extract, 
a protease was judged to be present. The positive results of this 
method are valuable; negative results cannot be taken as conclusive 
evidence that no proteolytic enzyme is present, since all proteases 
do not attack gelatin, and phenol is said to have an inhibitory influ- 
ence on the action of some enzymes. These investigators succeeded 
in showing that proteases occur in a great diversity of plants and 
of plant parts. Their negative results are sufficiently numerous 
™ VinEs, Annals of Botany 16:12. 1902. 
12 FERMI and BuscaLiont, Centralbl. Bact., etc., II. 5:24. 1899- 
