222 THE MICROSCOPE AND ITS REVELATIONS. 



CHAPTER VI. 

 MICROSCOPIC FORMS OF VEGETABLE LIFE. SIMPLER ALGJ3. 



218. THOSE who desire to make themselves familiar with Microscopic? 

 appearances, and to acquire dexterity in Microscopic manipulation, can- 

 not do better than educate themselves for more difficult inquiries by the 

 study of those humblest types of Vegetation, which present Organic 

 Structure under its most elementary aspect. And such as desire to 

 search out the nature and conditions of Living Action, will find in the 

 study of its simplest manifestations the best clue to the analysis of those 

 intricate and diversified combinations, under which it presents itself in 

 the highest Animal Organisms. For it has now been put beyond ques- 

 tion, that the fundamental phenomena of Life are identical in Plants and 

 in Animals; and that the living substance which exhibits them is of a 

 nature essentially the same throughout both Kingdoms. The determi- 

 nation of this general fact, which forms the basis of the Science of 

 BIOLOGY, is the most important result of modern Microscopic inquiry; 

 and the illustration of it will be kept constantly in view, in the exposi- 

 tion now to be given of the chief applications of the Microscope to the 

 study of those minute Protophytes (or simplest forms of Plant-life), with 

 whose form and structure, and with whose very existence in many cases, 

 we can only acquaint ourselves by its aid. 



219. It was formerly supposed that living action could only be 

 exhibited by organized structure. But we now know that all the func- 

 tions of Life may be carried on by minute 'jelly- specks,' in whose appar- 

 ently homogeneous semi-fluid substance nothing like ' organization 9 can 

 be detected; and further, that even in the very highest organisms, which 

 present us with the greatest variety of ' differentiated ' structures, the 

 essential part of the Life-work is done by the same material these 

 structures merely furnishing the mechanism (so to speak) through which 

 its wonderful properties exert themselves. Hence this substance, * known 

 in Vegetable Physiology as protoplasm, but often referred to by Zoolo- 

 gists as sarcode, has been appropriately designated by Prof. Huxley "the 



1 Attention was drawn in 1835 by Dujardin (the French Zoologist to whom we 

 owe the transfer of the Foraminifera from the highest to the lowest place among 

 Invertebrate Animals), to the fact that the bodies of some of the lowest members 

 of the Animal kingdom consist of a structureless, semi-fluid, contractile sub- 

 stance, to which he gave the name sarcode (rudimentary flesh). In 1851, the 

 eminent botanist Von Mohl showed that a similar substance forms the essential 

 constituent of the cells of Plants, and termed it protoplasm (primitive plastic or 

 organizable material). And in 1863 it was pointed out by Prof. Max Schultze, 

 who had made a special study of the Rhizppocl group, that the ' sarcode' of Ani- 

 mals and the ' protoplasm' of Plants are identical. See his Memoir " Ueber das 

 Protoplasma der Rhizopoden und Pflanzenzellen." 



