Knott — On Abnormalities in Human Myology. 4:'2!7 



distinct muscle in the vast majority of cases I have examined. This 

 has also been the experience of Professor Macalister. 



Gluteus quartus; invertor femoris ; scansorius. — This muscle is formed 

 by a differentiated portion of the anterior part of the glutaeus minimus. 

 "When present its origin reaches as high as the anterior superior spine 

 of the ilium. I have found it very distinct in three cases. 



Gemellus superior. — This muscle I have found frequently absent. 

 The inferior muscle I have never missed. 



Quadratus femoris was found completely absent in two instances. 

 One of these has been already published. 



Biceps flexor cruris. — A third head to this muscle from the upper 

 part ^i the linea aspera I have once seen. Absence of the short head 

 was noted in two instances. 



Gastrocnemius. — A third head of this muscle from the popliteal 

 surface of the femur I have twice seen {gastrocnemius tertius, Krause). 

 Accessory fibres of outer head arising from the external lateral liga- 

 ment of the knee-joint I have found present in five instances. 



Popliteus. — I have once found an accessory slip to this muscle arising 

 above the normal popliteus from the external condyle of the femur. 



Tensor capsuli tihio-tar salts. — A very well developed specimen of 

 this muscle I have once met with, arising from the outer surface of the 

 tibia for the lower third, below and outside the tibialis anticus, and going 

 to be inserted into the anterior annular ligament of the ankle-joint. 



Peroneus quartus (Otto) ; sextus (Macalister) ; p. accessorius. — Of 

 this muscle I have found one well-developed specimen (already pub- 

 lished). It arose from the lower part of outer surface of fibula, where 

 its fibres were found continuous with the lower part of the peroneus 

 brevis. The insertion was into the outer surface of the os calcis, just 

 behind the peroneal tubercle. 



Peroneo-tihialis. — Arises from inner side of fibula just below the 

 head, and is inserted into the oblique line of the tibia. Krause says 

 it is present in eighteen per cent, of the subjects examined, and con- 

 siders it analogous to the ulnar head of pronator radii teres. I have 

 found it four times in forty -nine subjects in which it was specially 

 looked for. 



Pronator pedis; peroneo-calcaneus internus. — Arises from the fibula 

 beneath and outside the origin of the flexor longus pollicis, and is 

 inserted into the inside of the os calcis. It was considered by Meckel 

 to be the analogue of the pronator quadratus in the upper extremity. 

 I have seen but one example. The insertion was into the sustentacu- 

 lum tali. 



Besides the anomalies enumerated in the preceding pages, I have 

 in my possession scattered notes of a considerable number, still un- 

 classified, chiefly of the muscles of the lower extremity, which time 

 has not permitted me to tabulate, but of which I shall take the 

 €arliest opportunity that time may afford to publish a complete list. 



