1889.] NATURAL SCIENCES OF PHILADELPHIA. 39 



to the pectoral group, and is apparently a muscle of respiration, when 

 functionable. Its nerve supply was found uniformly to come from 

 the anterior thoracic by Cunningham ; Shepherd found the same 

 innervation in each of twelve muscles, two of which, however, had 

 also an additional supply from the intercostals. Bardeleben, * who, 

 however, completely ignores the researches of Cunningham and 

 Shepherd, states that the nerve supply, wherever he has traced it, 

 has been invariably from the third and fourth intercostals. The 

 evidence, however, seems to be against Bardeleben. Based upon 

 this innervation, Bardeleben gives the following opinion : " Die In- 

 nervirung dieser typischer Varietat, wie ich sie bezeichnen mochte, 

 geschieht soweit Untersuchungen vorlegen, durch intercostal" and, 

 as the rectus abdominis has the same innervation, we must consider 

 the sternalis as a continuation of that muscle. He would call the 

 muscle " Rectus thoracis superficialis". He believes the muscle to be 

 vestigial. His " typscher Varietat" is that here figured. 



The case here described would be worthy of record, if only for the 

 extraordinary development of the muscle, on both sides, but there 

 are other facts connected therewith that give it an additional interest. 

 My attention was called to the muscles by two students, Messrs. 

 C. A. Tuttle and TV. P. Baldwin, in the practical anatomy room of 

 Yale. The subject was that of a male above thirty years of age, 

 much below the ordinary stature, and of slender, almost delicate 

 structure throughout. On the left side the muscle was nearly an 



inch and a half in its greatest width, 

 flattened, and nearly symmetrically 

 narrowed to its tendinous " inser- 

 tion." The round tendon began a 

 little below the cartilage of the sec- 

 ond rib, and was continuous with the 

 outer part of the tendon of the ster- 

 nomastoid, on which there were no 

 fleshy fibres for some distance above 

 the upper border of the manubrium. 

 Over the cartilage of the fifth rib 

 the muscle became rather suddenly 

 aponeurotic and continuous with 

 the sheath of the rectus abdominis. 

 The glistening aponeurotic fibres 

 diverged, fan-shaped, the larger part 



*Anatomischer Anzeiger iii, 324, 1 



