10 BRUCE—ON THE ACTIVITY OF 
described by F. X. Lang,* are of two kinds: sessile glands 
arranged more or less in rows, and stalked glands, which are not 
so numerous as the sessile ones. The heads of the stalked glands 
are surrounded by a glistening drop of secretion, which is always 
absent from the sessile glands. Their secretion is neutral to 
litmus paper. In no case did I find an acid reaction. In being 
neutral it agrees with the secretion from the tentacles of 
Drosera, but differs from that of Drosophyllum lusitanicum, 
which is strongly acid. The head of the stalked glands does 
not contain any purple fluid. Darwin mentions as the outcome 
of his examination of dried specimens that “the glands of 
Byblis are purplish”; this I did not find to be the case in the 
living plant of Byblis gigantea. 
Experiment I. 
In order to determine if the tentacles possess the power 
of movement, I examined many tentacles to which insects 
were adhering, but was quite unable to discover any signs 
of inflection; nor was any sign of movement to be 
detected on irritating the tentacles with a needle nor on 
scratching or pricking the blades. This is what might 
have been expected, since the pedicel of the stalked glands 
is unicellular, and, according to Sachs, “no instance is 
known of any unicellular structure possessing the power 
of motion.” 
Experiment II. 
A small cube of albumen about 1 mm. in size was 
placed on the sessile glands, and after 48 hours was com- 
pletely surrounded by an acid secretion. On examining 
the cube with a lens, it was seen that the edges and 
corners had been rounded off. After three days, the cube 
was represented by a small round white spot in the 
centre of a drop of secretion. At the close of the fourth 
day, this white spot had become smaller, and next day 
had completely disappeared. 
¥F, X. Lang, TT 2 1 i1¢ enent 
wicklung von Pelpheubielex und gates gigantea, in F es met: 
