56 
THE AMERICAN BOTANIST. 
North America, and Nepenthes, the pitcher-plant of the East In- 
dies, etc. The question arises — How is it that plants of no af- 
finity have acquired this common property ? Though it is difficult 
even to guess how the widely different structures came into exist- 
ence in each case respectively, we may safely attribute it, at least 
in a general way, to protoplasm, which is the same in all plants 
and animals. Hence, whatever the causes may have been which 
excited it to develop insectivorous structures, it is not surprising to 
find such in plants of no relationship beyond the common bond of 
vegetable life bound up in the living protoplasm. We have seen 
that when any nitrogenous matter is placed upon an insectivorous 
organ a digestive fluid and an acid are secreted in an exactly com- 
parable manner to the behaviour of our own digestive apparatus. 
Now, there are several instances known where this is effected 
among plants quite apart from truly insectivorous habits at all. 
Thus, the papaw tree of the West Indies, etc., has large leaves not 
unlike those of the fig, and pear-like fruits. It has long been 
known, and, indeed, used for the purpose, that if tough meat be 
wrapped up in the leaves or rubbed with the cut fruit it becomes 
tender. A fig leaf will answer the purpose as well. The fact is 
that the presence of nitrogenous substances stimulates the proto- 
plasm to secret the digestive fluids, and the making the meat ten- 
der is really due to- what might be called ^^ncipient digestion." 
Knowing this common property of protoplasm. Dr. M. T. 
Masters placed fragments of hard boiled white of egg in the little 
nectaries of the Christmas rose. After a certain time they exhib- 
ited the usual feature of "aggregation" in the cells of the nectaries 
always seen when insectivorous plants have consumed their prey. 
This experiment proved that incipient digestion had been set up, 
though, of course, these honey-secreting organs are not naturally 
insectivorous at all. 
The butterworts derived this name from the fact that they will 
curdle milk, they are used in Lapland for making a cheese-like sub- 
stance from the milk of the reindeer. Our common Lady's bed- 
straw {Galium verum) with yellow flowers possesses an analog- 
ous property, and has long been used as a sort of vegetable ren- 
