INTKODUCTION PROTOPLASM THE CELL 



spongioplasm frequently presents a finely granular appearance, 

 which is so universal in its occurrence as to have led to the pro- 

 mulgation of the now discarded granular theory of protoplasmic 

 structure, so ably supported by Altmaim. These fine granules, 

 termed microsomes by Hanstein, as well as the coarser granules of 

 paraplasm, appear to be strictly confined to the spongioplasmic 



reticulum, the larger and therefore 

 more frequently observed granules 

 occurring at the intersections of this 

 network (Biitschli).* 



There is still some doubt as to the 

 exact character of the reticulum and 

 its matrix, and as to the microscop- 

 ical substances of which they are the 

 optical expression. All observers are 

 now practically agreed upon the fluid 

 nature of the matrix, or hyaloplasm ; 

 the interpretation of the network is 

 still the subject of discussion. 



The fibrous nature of this network, 

 though not explaining all the pecul- 

 iarities of protoplasmic structure, 

 had come to be quite generally ac- 

 cepted, until the convincing studies 

 of Biitschli upon the structure of 

 protoplasm as related to that of cer- 

 tain microscopic oil foams, coagulated 

 proteid solutions, etc., showed that 

 the reticular structure of protoplasm 

 could be almost exactly simulated by 

 the artificial combination of fluids 

 of different consistence to produce a 

 microscopic foam. Biitschli there- 

 fore regards protoplasm as composed of fluid alveoli of not over 

 0.001 millimeter in diameter, between and surrounding which is 

 a denser fluid coating, whose section produces the characteristic 

 optical appearance of a true reticulum. That this theory possesses 

 at least a considerable essence of truth is evident from the very 

 able and conclusive demonstrations of its author. 



Jfe 



FlG. 4. AN EPIDERMAL SUPPORTING 

 CELL OF LUMBBICUS TERRE9TUIS, 

 ILLUSTRATING THE ALVEOLAR 

 STRUCTURE OF PROTOPLASM. 



c, cuticle. Very highly magnified. 

 (After Biitschli.) 



* London, 1894. 



