THE YOUNG NATUEALIST. 



103 



non-scientific readers than the subject matter 

 of this brief paper. Without going at all 

 into the fierce controversies which have raged 

 round this harmless substance, I wish, if 

 possible, to explain concisely and plainly 

 what is meant by Protoplasm, where it is 

 found, and what are its functions, with more 

 special reference to its place in the economy 

 of vegetable life. Many years ago naturalists 

 observed that the bodies of some of the 

 lowest members of the animal kingdom were 

 entirely composed of a structureless, semi- 

 fluid, contractile substance, to which the 

 name of s'arcode was given, and almost 

 simultaneously a similar substance was 

 noticed in the cells of plants, to which the 

 name Protoplasm was given. Farther re- 

 search soon showed that these two apparently 

 similar substances were identical, and that it 

 formed the biological boundary, or union 

 line, common to both the animal and vege- 

 table kingdoms, and inherent to and inseper- 

 able from vital action. Plence Prof. Huxley 

 has well called it "the physical basis of life," 

 a definition which has never been equalled, 

 and will probably never be excelled. Sowve 

 may look upon Protoplasm as the starting 

 point of life, or vital energy, as distinct from 

 dead, inert, lifeless matter ; but. although 

 co-extensive with its manifestation, it is not 

 asserted to be the cause of all the phenomena 

 of existence. One of the neatest of epigrams 

 was thrown off at a recent meeting of the 

 British Association when Prof. Allman was 

 President, and the subject of his address, 

 Protoplasm . — • 



" From life to consciousness the chasm 

 Can not be bridged by Protoplasm ; 

 Motion is life ; but chlorophyll 

 Can Allman 's duty not fulfil." 

 Chemically considered Protoplasm is com- 

 posed of the four elements, Carbon, Oxygen, 

 Hydrogen, Nitrogen, with traces of sulphur. 

 Chemists are not entirely agreed as to the 

 exact relative proportions, but carbon forms 

 by far the largest part, being more than half 

 of the whole mass. Protoplasm in the pure 

 state is found as a shapeless, structureless, 



semi-fluid, transparent substance, of a glairy, 

 tenacious consistency, very similar in appear- 

 ance to the white of egg, but endowed with 

 irritability, or the power of motion. Deep 

 sea dredgings have furnished masses of oozy 

 slime, which has been found to be pure Pro- 

 toplasm. Portions viewed under the micro- 

 scope exhibit most peculiar motions, stream- 

 ing away in every direction, then retreating 

 and contracting, again to branch out in ever 

 varied form ; never still, but instinct with life, 

 although the highest power of the microscope 

 fails to detect anything in the shape of 

 organised structure. A similar substance 

 has been found in fresh waters on the Con- 

 tinent, portions of which have been observed 

 to divide spontaneously, the fragments soon 

 attaining the proportions and properties of 

 the parent, or original mass. Slightly farther 

 advanced in the scale of being, in stagnant 

 pools. &c, may be found the Amaba, in which 

 we find the first traces of organisation, in the 

 form of a small globular portion of the Pro- 

 toplasm, which appears of a firmer con- 

 sistency, and is called the nucleus ; whilst 

 the boundary of the mass seems invested by 

 an incipient membrane of a slightly firmer 

 texture, but its shape and form are so chang- 

 able as to be perfectly indefinable. Whilst 

 you watch, from any part of the surface, 

 finger-like processes may be protruded ; if 

 they come in contact with any solid substance 

 suitable for its food, they encircle it, and it is 

 withdrawn into the mass, if any indigestible 

 portion remains, an opening is made any- 

 where in the creature, and it is ejected. This 

 process is constantly going on, so . that its 

 form is continually changing. They increase 

 by division into two equal parts, which 

 immediately assume the functions and rapidly 

 attain the dimensions of their original parent. 

 Thus we see the Amcsba feeds, grows, and 

 multiplies, and is yet only a shapeless mass 

 of Protoplasm. An exactly similar organism 

 is seen in the white corpuscles of the blood 

 in man, and other animals. 



(To be continued.) 



