Reviews and Records in Anatomy and Physiology. 91 
wise, forming large dises—the cleavage taking place, from the 
exact coaptation of the discs, through the light spaces. 
Nothing can be more clear than the structure of a tissue thus 
Wrought out, and with such data the student who has once caught 
its formula by an observation through the microscope on a good 
specimen, will never have his zdea of striated muscle effaced,— 
for this in general is the elementary composition of voluntary 
muscular fibre wherever found, as a striated structure, among all 
imals. 
Leaving for a future page a criticism of some of the points of 
Bowman’s doctrine, we will continue our subject by some refer- 
ence to the development of this tissue. Undoubtedly the most 
important because the most comprehensive researches that have 
eeti made in this direction are those of Kolliker and Lebert. 
The two leading features in the primary formation of muscle, are, 
first, that its origin is cellular, and second, that the fibre and not 
the fibrilla is the primary part evolved—the fibrilla being there- 
fore a secondary or resultant formation. 
The fibre is a more or less direct result of a fusion of a row of 
cells together :—this is the foundation ; and the secondary changes 
which supervene thereon vary in extent and character according 
to the more or less complexity of the form of tissue ultimately 
evolved. The details of this genesis we need not here describe ; 
all we wish to indicate is the original cell-constitution of muscular 
tissue in every locality where it is found; it might also be added 
that its departure from this original cell-condition and the meta- 
morphosis of these cells into more or less complicated forms, holds 
a nearly corresponding ratio to the grade either of the animal in 
the scale of life, or of the function the particular tissue in ques- 
tion is to perform. 
But these remarks, with the exception of the last general state- 
ment, refer particularly to the striated form of muscular fibre, to 
which the observations of Bowman and Lebert relate almost 
although they are, it is trne, connected with the functions of the 
organic or non-voluntary life. Upon this subject, at least as con- 
nected with the higher animals, no single observer has thrown so 
much light as Kdélliker. This excellent observer showed that 
the elements of the smooth or non-striated muscles, do not con- 
sist, as had hitherto been supposed, of long bread bands dotted 
with many nuclei, but are composed of comparatively short, isola- 
ted fibres, each of which contains a nucleus. ‘The cell origin and 
Constitution of these fibres | eepoeabe are too apparent to 
questioned. But these cellS have experienced but few changes, 
and have undergone none of those elaborate alterations which 
similar cells form the striated variety of | 
Supervene when 
