242 ABSORPTION-CELLS ON LEAVES. 



infrequently killed accidentally in the water filling the larger kinds of basins 

 formed as parts of foliage-leaves, that pollen, spores, and particles of earth also are 

 blown by the wind into these basins, and that, after the ensuing solution and 

 decomposition of the organic and mineral bodies in question, the water exhibits a 

 brownish colour and contains organic compounds as well as food-salts in solution. 

 It is not necessary to repeat that these compounds are able to pass into the interior 

 of the plant with the water through the action of the absorption-cells which are 

 never absent from the bottom of the basins; but it seems proper to consider 

 specially in this connection the most conspicuous cases of the phenomenon which 

 have been observed. The greatest quantity of matter, dissolved and undissolved, is 

 found in the flat, saucer-shaped laminae of Saxifraga peltata, which grows on the 

 sites of springs in the Sierra Nevada of North America. The water in these saucers 

 is sometimes coloured quite a dark brown by the presence of decayed beetles, wasps, 

 centipedes, fallen leaves, and animal excreta; and when it evaporates a regular crust 

 is left behind at the bottom of the reservoir. Three days after rain I still found in 

 the inflated vagina of Heracleum palmatwrn,, a species of cow-parsnip, a pool of 

 brown water 2 cm. deep, and at the bottom a deposit of blackish, oily mud in which 

 the remains of decayed earwigs, beetles, and spiders, were still recognizable. The 

 same thing is observed in the cisterns of Bromeliacese and in the water-basins of 

 Dipsacus laciniatus and Silphium, perfoliatum (fig. 56), and it is interesting to 

 find there are cells also at the bottom of the basins of the Dipsacus in question from 

 which protoplasmic threads radiate forth, as in the case of the chambers of the 

 Tooth wort, and that numberless putrefactive bacteria always make their appearance 

 in the water in these basins. The quantity of organic residue is less considerable 

 in the saucer-shaped leaves of pelargoniums, but, on the other hand, earthy particles 

 are frequently met with in them to such an extent that, when the water has 

 evaporated, the concave surface of the leaf is covered with an ashen-gray layer 

 of earth. 



Observations of this nature establish the conviction that no sharp line of 

 demarcation exists in respect of the absorption of water either between carnivorous 

 plants and land plants, or between land plants and saprophytes, or between 

 saprophytes and carnivorous plants; and they lead further to the conclusion that 

 water, mineral food-salts, and organic compounds are susceptible of being taken up 

 not only by subterranean but also by aerial absorptive apparatus. 



