758 
MR P. BRUCE WHITE ON 
while in fig. 5 the substance of a highly atrophied fibre (A) is contrasted with two 
normal fibrillse and normal sarcosomes (B). 
The sarcosomes of the atrophied fibre are much denser and more cubical in shape 
than the normal granules, and may be of relatively enormous size. In highly 
degenerate fibres they may form conglomerate masses of considerable size. 
When degenerate muscle is treated with dilute acetic acid the fibrillar vestiges 
swell, forcing the granular columns apart, and a picture closely resembling normal 
muscle when treated in the same way is achieved. 
When freshly obtained normal and atrophied fibres are placed in a drop of dilute 
eosin or methylene blue, it is found that while the former are only slowly and 
superficially stained, the latter become rapidly and deeply stained through their 
entire substance. This would seem to indicate that the degenerate fibres are dead. 
Though various fixation and staining methods have been employed, they have 
added little to the facts derived from the study of fresh material. 
These muscle changes may be summarised as — 
A general wastage of the fibrillar substance and loss of sarcous fluid, with the 
condensation of the frequently enlarged sarcosomes in densely arranged longitu- 
dinal columns, the process resulting in a shrinkage of the fibre with loss of function. 
All stages in this process are, of course, to be encountered. 
A further feature of some atrophied fibres, and occasionally of those which do not 
show the typical signs of wastage, is the development of pigmented spots in their 
substance. Such spots are represented in fig. 5. 
These spots vary in colour from yellow to a deep brown or black, and often 
appear to bear a definite relationship to the distribution of the tracheoles supplying 
the muscles. 
Careful scrutiny has not entirely elucidated their origin. It seems possible that 
they may be caused by staining of the muscle by the fsecal dye of the parasite, which 
has percolated into the final ramifications of the tracheal system. 
Other explanations which have been considered are that the discoloration is due 
to a degenerative process in the muscle or to an accumulation of waste products. 
This point may perhaps be cleared up by further work. 
In some diseased stocks these spots are found in almost every crawling bee ; in 
others, apparently at the same stage of the disease, they are absent. 
The Blood. 
The blood of the crawling bee is often scanty, though when such bees are 
warmed and fed they recover their normal complement of body fluid. 
No qualitative cytological difference has been noted between the blood of healthy 
and crawling bees, though the number of cells per unit volume may be increased in 
the latter. This increase is probably entirely due to loss of plasma and cannot be 
regarded as a leucocytosis. 
