NOTE BY THE TRANSLATOR. 433 



unstriped muscles of invertebrates there does not appear to be an 

 intracellular network present in. any form, but in the unstriped 

 muscle of vertebrates there are longitudinal fibres only; these 

 possibly represent a form of network intermediate between the 

 typical irregular intracellular network of other cells and the highly 

 modified network of striped muscle. 



6. The cardiac muscle-cells contain a network similar to that of 

 ordinary striped muscle. 



