86 A TEXTBOOK OF GENERAL BOTANY 
Plants of the genus Utricularia, some of which are submerged 
aquatics, are provided with bladders that entrap small animals 
in very much the same way as an ordinary trap catches a rat 
(Fig. 78). These 
bladders are pro- 
| vided with trap 
\ doors which allow 
the animals to en- 
ter and then bar 
their exit (Fig. 78). 
Small crustaceans 
may remain alive 
in these bladders 
for a considerable 
length of time, and 
it is probable that 
some of the prod- 
ucts of their ex- 

sees 
x 


i r: c s Be” ea © 5) 
8 6 AG? * S's creta are absorbed 
» OF | ees by the plant. They 
RDO VIRGO St EY : 
spoguere HEP" Soap finally die and are 
od decomposed by the 
ot} x a 2 
oe "Sq action of bacteria. 
: Eee ioe Nitrogenous prod- 
ucts, which can be 
absorbed by the 
plants, are thus 
The horizontal stemlike structures are modified leaves 7: 
: liberated. 
which bear leaflike outgrowths and animal-catching f 
bladders and function as roots. (x 1) Some species of 
Utricularia live in 
water (Hig. 78), while others grow on a very moist substratum 
(Fig. 79). The latter have aérial shoots which bear flowers. In 
some forms there are ordinary leaves near the base of the plant, 
and also structures (Fig. 79) which are morphologically leaves 
but which have the appearance of horizontal branches and bear 
leaflike outgrowths and also animal-catching bladders. These 
Fre. 79. A Utricularia that lives on a very moist 
substratum 
