GEDGE, ON MOTOR NERVE. 195 
have never seen them within the sarcolemma. Neither have 
I ever seen the sarcolemma become puckered around a con- 
tracted muscular fibre. Sometimes a fibre shrinks within its 
sheath, and has a wavy appearance ; but then the sarcolemma 
may be seen tightly strained, spanning across the concavities 
of its undulating margin. The sheath described by Dr. 
Moxon as the sarcolemma is in reality the fascia of the 
antennal muscle. 
Fascie, composed of a connective tissue, do exist in the 
muscles of insects. Let any observer obtain a pupa of one 
of the Sphingide for instance, and this he can do without 
waiting until the spring.* ‘Then, having removed the upper 
half of the abdominal part of the pupa, and cleaned away the 
fat from it, he will see four dorsal segment-muscles. Soak 
these in water, or, better still, in glycerine containing two or 
three drops of acetic acid to the ounce, or prepare them with 
a slightly alkaline solution of carmine. The objection, how- 
ever, to this latter method in this particular, is that the time 
required for soaking is sufficient to allow the fluid to drive 
the air out of the trachea, and then the nuclei, which by this 
method I am always able to demonstrate at regular intervals 
along the tracheal sheath, would lead to confusion and mis- 
understanding. When prepared, detach one of these muscles 
from its anterior and posterior attachment, and it will be 
found to separate at once into a number of distinct fasciculi. 
These contain a variable number of muscular fibres bound 
together by extremely delicate tissue, corresponding in posi- 
tion to the connective tissue of higher animals. Beneath this 
delicate investment, but outside the sarcolemma of the con- 
tained fibres, nuclei precisely similar to those described by 
Dr. Moxon may be demonstrated. The tissue which invests 
these fibres and glues them together, though here it has no 
certain structure,is, I believe, true connective tissue, modified 
in structure only in proportion to the modifications observable 
in other tissues. Every muscle in the insect, and every fas- 
ciculus, whatever the number of contained fibres, has its 
fascia. 
These nuclei, though they lie along the edge of the muscu- 
lar fibres, are often very numerous, and, if carefully examined, 
may be seen to be on different planes. Why they should 
generally be visible only along the edge of the muscular fibres 
is not easy to see, but doubtless it arises in part from the 
difficulty of seeing them when they are backed by the muscle, 
and partly in consequence of these gibbous nuclei being dis- 
posed in an almost diffluent medium, the slightest pressure 
* This paper was written in the beginning of January. 
