THE HISTOLOGY OF THE STEIPED MUSCLE FIBRE. 239 



cause of the transverse striation is different here from that in the 

 insect. 



I have received the greatest sympathy during this investigation 

 from my friend Mr. C. F. Marshall, with whom I have verified most 

 of my results. The drawings of the network in the fibres of the Eat 

 and Lobster are from gold preparations by him. Mr. Marshall is at 

 present working on the histology of the muscle fibre, from the lowest 

 types of the animal kingdom in which it occurs upwards, and has 

 already obtained interesting results. A study of the comparative 

 development or phylogeny of this network, and at the same time of 

 its embryology, may lead to its undoubted recognition as an ordinary 

 intracellular network. 



My thanks are also due to Professor Milnes Marshall, who has kindly 

 examined my drawings and specimens, and suggested alterations in the 

 paper, and to Mr. J. Priestley. 



Brief Summary of Eesults. 



The chief results at which I have arrived may be summarised as 

 follows : 



There is an intracellular network present in the striped muscle fibre 

 of Dytiscus, Bee, Lobster, Crayfish, Frog, and Bat, which may be 

 most clearly demonstrated by certain methods of gold staining. The 

 network alone is stained by the reduced gold, and, owing to this 

 differentiation, is plainly visible even with comparatively low powers. 

 This network may be demonstrated, though not so completely, in the 

 living fibre, and in acetic and osmic acid preparations. 



Crossing the fibre transversely, united to the sarcolemma, and more 

 or less separating the muscle fibre into compartments, are network 

 partitions — the transverse network. 



Kunning longitudinally down each compartment, and joining the 

 dots at the intersections of the fibres of the transverse network, are a 

 series of fine rods. The arrangement of this network will be made 

 evident by reference to diagrams 1, 2, 3, and 4. 



This network consists of an isotropous material, and is more highly 

 refractile than the rest of the muscle substance, which is anisotropous. 

 This network serves to explain the transverse striation and other 

 complicated appearances presented by the muscle fibre, and brings 

 into harmony many of the conflicting statements of histologists on 

 this subject. 



