THE HISTOLOGY OP THE STRIPED MUSCLE FIBRE. 231 



(b) Bee. 



Insect muscle may be very conveniently obtained from the thorax 

 or leg of a bumble bee. 



Prepared with acetic acid and gold chloride, by the method already 

 described, it shows a network identical with that described in Dy tiscus. 



In order to obtain muscle in as uncontracted a condition as possible, 

 gold preparations were made from the leg muscles of a bee, rendered 

 insensible and immovable by chloroform vapour, in which presumably 

 there was complete relaxation of the muscle fibre. These prepara- 

 tions, however, could not be distinguished from those prepared without 

 chloroform. 



As the fibres are rendered soft by the method of preparation their 

 size and the size of their elements varies with the pressure of the 

 cover-slip ; hence measurements are of little or no value. 



(c) Frog. 



The fibres from the gastrocnemius of the frog treated by the 

 same gold method as before yield an unmistakeable network. The 

 fibres when examined are seen to be more changed by the process 

 than is the case with insect muscle. They become very much softened, 

 and when pressed upon by the cover-slip expand to many times their 

 natural diameter, and thus often altogether lose their shape. Owing 

 to this disturbance of the fibre the network usually shows no distinct 

 differentiation into horizontal or transverse, and longitudinal portions. 

 Hence there is no transverse striation. 



In many places in the preparation isolated portions of fibre show a 

 network with polygonal meshes as in fig. 7. This network is also seen 

 at the ends of certain fibres which, curling up, show a transverse 

 section. The meshes are often, when the fibre is much expanded by 

 compression, large enough to be seen with Zeiss A. obj., at other times 

 much smaller, approximating in size to the meshes of the horizontal 

 networks in insects' muscle. The size of the meshes seems to depend 

 entirely on the degree of compression of the fibre. When the meshes 

 are small, distinct thickenings or dots are seen at the intersections of 

 the fibres composing the network. This network is particularly sharply 

 defined and is plainly seen to be a true network, that is, the hues 

 represent linear fibres only. It is not a honeycomb work. The lines 

 do not represent the edges of plates of interfibrillar material, 



