MICHIGAN ACADEMY OF SCIENCE. 
171 
THE OCCURRENCE OF A CREMASTER MUSCLE IN A WOMAN. 
G. MORRIS CURTIS. 
This rather unusual anomaly, the occurrence of a distinct Cremaster 
muscle in a human female, is presented, not with the idea of bringing 
out any point in the structure or development of the human muscular 
system, but rather for the purpose of adding another to the long list of 
anomalies found in adult structure,' which can be traced to embryolog-. 
ical causes. This particular case represents a condition in which an em- 
bryological structure, normally retained and made use of by the male 
only, is retained by the female because of developmental factors. 
The Cremaster muscle is a thin band of muscular fibers, present nor- 
mally in the male only, which suspends the testis within the scrotum, 
attaching to the body wall above; its literal meaning being to suspend. 
It is supposed to be derived by the dragging down of muscular fibers! 
from the lower border of the abdominal muscles, as the testis descends 
to its adult position. 
Its function is to draw the testis up toward the external inguinal 
ring or the inguinal canal, this function being more or less developed in 
man and well developed in rats and squirrels, which can completely 
retract the testes through the inguinal canal into the body cavity. It 
may also serve as an additional support to the testis, in some cases, 
for example in the cat, being represented by a dense fibrous fascia, 
which is said to be formed from the degeneration of the muscular ele- 
ments. 
That its fibers are voluntary and are derived from striped muscle is 
evident histologically and in this it differs from the so called Cremaster 
interims of Henle , which is of non-striped muscle and is situated at the 
distal end of the testis and separated from it by the infundibuliform 
fascia. 
The muscle is described by McMurrich (in Piersol’s Anatomy, p. 519) 
as follows : “The Cremaster muscle consists of a series of somewhat 
scattered loops of muscle tissue derived from the lower part of the 
internal oblique and to a slight extent from the transversalis. It is 
attached laterally to Poupart’s ligament and medially to the anterior 
layer of the sheath of the rectus. The loops descend through the in- 
guinal canal along with the spermatic cord, the muscle being well de- 
veloped only in the male, and spread out in the tunica vaginalis com- 
munis of the testis and spermatic cord. The loops are united by con- 
nective tissue which forms part of the cremasteric fascia. Nerve supply, 
by the genital branch of the genito-crural nerve. Action, to draw the 
testis upward towards the external abdominal ring.” 
The case to be described was found in the dissecting rooms of the 
Anatomical Laboratory of the University of Michigan. The cadaver 
was that of a young woman of medium height, much emaciated by tu- 
