PLANT INTELLIGENCE 
with plants, is an acute sense of taste. How else 
do the plants know what elements to absorb out 
of the soil? Certain experiments have enabled 
investigators to discover marked taste prefer- 
ences of a number of microscopic plants. Bac- 
teria are exceptionally fond of kali salts. 
Though they thrive equally well on glycerine, 
they can be lured from it at any time by the 
toothsome kali solution. 
A sense of taste plays a remarkable part in 
the fecundation of Moss. The male element is 
composed of swift-swimming cells equipped 
with vibratory hairs. When deposited by the 
wind or other means on the cups of the female 
flower, they swim about in the moisture until 
they are eventually enticed to the unfertilized 
eggs at the bottom by their taste for malic 
acid. That this is no idle theory can be 
proved in the laboratory. The seed-animal- 
icules of some of the Ferns also are urged to 
the act of impregnation by their preference for 
the sugar in the seed cups. 
All through the plant world we see actions 
and habits which are the reverse of automatism 
or mere instinctive response. Every plant con- 
[190] 
