76 
MONDAY, JUNE 28, 1858. 
James Hentuorn Topp, D. D., President, in the Chair. 
Dr. Lyons, on the part of the Commission appointed by the Council on 
March 1st, presented and made some remarks on— 
THE REPORT ON THE CASE OF M. GROUX. 
Tue case of M. Groux, on which we have been instructed to report by 
the President and Council of the Royal Irish Academy, is an example 
of bifid sternum, or congenital fissure of that bone, a condition noticed 
by Meckel, Breschet, Serres, and Geoffrey St. Hilaire. By the two last 
investigators it has been specially instanced in support of the doctrine 
of osseous development being conducted in conformity with the laws of 
‘‘ bilateral symmetry,’’ and central conjunction. This bifid sternum, 
like the bifid spine and the remaining examples of the symmetric ca- 
tegory of Serres, depends on the arrest of growth. 
When M.Groux’s arms are not extended, and the pectoral muscles are 
relaxed, this depression is an inch in width when measured at the termi- 
nation of the third rib. The integuments pass into and across this 
groove, and present no alteration of structure or adhesion; they can be 
pinched up and drawn outwards in a fold without any indication of the 
existence of a dense fascia or expansion beneath; into this groove the 
hollow at the lower portion of the neck is continued, uninterrupted by 
any bounding osseous line or inter-clavicular hgament; the sternal ends 
of the clavicles are small; the sternal portions of the sterno-mastoid 
muscles are not deficient, nor are their sternal tendons, which are in- 
serted into the edges of the bone immediately beneath each clavicle. 
The groove is closed transversely, and at the lower part by the ensiform 
cartilage, which is flat, broad, very firm, and overlapped on each side 
by the sternal ridges, with which it is connected by a strong but 
elastic medium. This is rendered very evident when M. Groux raises or 
throws back his arms, or when, having fixed the latter, he puts the 
pectoral muscles, which are well developed, into strong action: the fissure 
then becomes expanded to a width of nearly three inches. When, on 
the contrary, the shoulders are brought forward, the fissure becomes 
nearly closed, and the clavicles touch and even overlap each other. 
Before proceeding to describe the most remarkable feature in this 
case, namely, the existence of a visibly pulsating tumour in the upper 
and middle parts of this fissure, we have to observe that there is no evi- 
dence, either from symptoms or physical signs, of the existence of any 
diseased condition of the heart, the great vessels, or the lungs. There 
is no visible pulsation in the veins of the neck. But a question might 
arise, namely, whether the organs of circulation might not themselves 
present some form of congenital malformation or malposition. On this 
point we have come to the conclusion that evidence of any of these con- 
ditions which might be expected in such a case—namely, defect of me- 
