6 PROPERTTES OF PROTOPLASM. 



Physical Properties of Protoplasm. — Protoplasm, 

 or living matter, is in itself usually colourless and trans- 

 parent. Its consistency varies considerably according to 

 the amount of contained water. There can be little doubt 

 that it is a physical as well as a chemical complex. 

 Differential staining and other methods reveal the existence 

 of a meshwork of more stable and less fluid substance, 

 sometimes termed spongioplasm^ and a more mobile and 

 less easily stained substance, sometimes termed hyaloplasm^ 

 which permeates the interstices of the spongioplasm. 

 Scattered throughout the hyaloplasm is a number of 

 minute bodies, readily stained and of unknown com- 

 position. They are called microsomata and may be con- 

 nected with the nutrition of the more essential living parts 

 of the protoplasm, as they decrease and are absorbed when 

 the protoplasm is starved. This idea is often extended to 

 include the hyaloplasm, which is thus regarded as merely 

 a nutrient fluid bathing the primary living spongioplasm, 

 but there is little certainty regarding these points. It is 

 important to notice that at least three physical constituents 

 of protoplasm can be discerned, and that its mobility, 

 fluidity and reactivity are directly related to the amount 

 of contained water. A number of the physical phenomena 

 of protoplasm, such as its mobile movements and change 

 of shape, can be closely imitated by small isolated oil 

 drops and other devices. 



Chemical Properties of Protoplasm.— It is very 



generally accepted that protoplasm is not a definite 

 chemical substance but a complex of several. If it be a 

 single substance it must be of so great instability as to 

 break up into its constituents as soon as it is formed. 

 Analysis shows that protoplasm consists of a number of 

 substances called proteids^ which are sufficiently definite 

 to come within the power of chemical manipulation. They 

 may be the first decomposition-products of protoplasm 

 itself, or they may be the actual constituents of protoplasm. 

 In other words, protoplasm is either a physical or a chemical 

 aggregate of proteids. 



Proteids are of very complex molecular composition, and are 

 known by definite chemical tests (such as the production of a violet 



