HUTCHINSON'S POPULAR BOTANY 



FIG. 39. CELLS OF WATER-THYME 

 (Elodea canadensis). 



Showing the directions of the currents of 

 protoplasm in the cells of the leaf. 



Briar-rose, so is it with all plants. The chemi- 

 cal constituents of protoplasm are the same 

 wherever you find it ; in the simple Fungus 

 (Penicillium glaucum) (fig. 40), which forms 

 .-, \ * f^ the green mould on stale food, as in the complex 



\ . jl organism of a Trumpet-flower or an Orchid. 



^ J jj^fiy/ The foregoing may appear to be a sweep- 



ing statement, involving as it does the 

 fundamental unity of all forms of vegetable 

 life ; but we may go much further than that 

 and say, with full sanction of modern Science, 

 that the protoplasm of the cells of which we. 

 and the entire membership of the Animal 

 Kingdom are built up, is essentially the same 

 as that which we have been considering in the 

 living plant. Formerly, the cell-matter of 

 animals was distinguished from that of plants 

 by the name of sarcode : but when Max Schultze 



and others established the fact that the matter was identical in animals 

 and plants, the distinguishing term was dropped, and now, whether we are 

 speaking of animal or vegetable organisms, the one word protoplasm is used 

 to denote its common nature. As a consequence of this identity of elemental 



structure, no one can say with certainty where 

 the Vegetable Kingdom ends and the Animal 

 Kingdom begins. The simplest plants are 

 grouped under the name of Protophyta, and 

 the simplest animals form a corresponding 

 group known as Protozoa : but in consulting 

 a modern natural history of plants and a 

 natural history of animals in turn, you will 

 find a number of species doing double 

 duty and appearing in each. Botanist and 

 zoologist alike claim them as their subjects. 

 The difficulty is increased by the fact that 

 many indubitable single-celled plants are in 

 their younger condition unhampered by the 

 wall of cellulose they secrete later, and with- 

 out which they are able to move freely, just 

 like similar organisms of undoubted animal 

 nature. The evolutionist, who contends that 

 animal and plant life have had a common 

 origin, gets over this difficulty by merging 

 Photophyta and Protozoa into a single group 

 under Haeckel's name of Protista. 



FIG. 40. GREEN MOULD (Peni- 

 cillium glaucum), 



Which rapidly grows on stale food. Each 



branch ends in a chain of spores, which fall 



away as they ripen. 



