888 MR. ST. GEORGE MIVART ON THE [ Dec. 6, 
The musculo- cutaneous (7) nerve descends between the flexors and 
the tibialis anticus, becoming superficial at the ankle. 
The anterior tibial nerve quits the one last noticed, and dipping 
between the popliteus and the flexor longus hallucis, comes out on 
the front of the leg above the peroneo-tibial, supplying the extensors. 
SERIAL HoMOLoGy OF THE APPENDICULAR MUSCLES. 
The question of the serial homology of the limbs has been lately 
considered by Professor Flower in his first course of Hunterian 
lectures*. He there followed out and developed certain views which 
I suggested in 18667, and which had more or less commended 
themselves to Professor Rolleston¢. I allude especially to the 
notion that the gluteus medius and minimus are the serial homo- 
logues of the subscapularis, and that similarly the iliacus is the serial 
representative of the supra- and infraspinatus. 
Against this Professor Humphry has quite recently raised some 
objections §, principally opposing any supposed rotation of the ilium 
similar to that which the whole pelvic limb undergoes during its 
development. , 
But in reply it may be said that a rotation of the ilium or scapula 
is by no means necessary to the view I before advocated. In speak- 
ing of such a possible rotation in connexion with the Echidna, I 
did so in deference to the authority of Professor Humphry, who 
had said|| of the ilium and scapula, “it is probable that they also 
participate, to some extent, in the rotation which the limbs undergo.” 
All that is necessary to conceive is that bony ridges are developed 
in one case which are suppressed in another, not that there is any 
rotation. This wasin my mind when I said {, “on the whole, I am 
inclined to believe that extended investigations will show that the 
scapula and ilium may most conveniently be regarded as, so to speak, 
essentially columnar bones, such as we find them in Chelonians, and 
serving to give origin to muscles inserted into the proximal bone of 
each limb, but varying in shape and size, and developing ridges or 
processes according to the exigencies of each case.” For this it is 
not necessary to suppose any alteration in the ventral parts of the 
limb-girdles. 
The singular limb-structure of the Chameleon, and the more than 
usual resemblance between the ilium and the scapula, made me 
look forward with great interest to the investigation of its myology. 
* See also his paper in the ‘Cambridge Journal of Anatomy and Physiology ’ 
for May 1870, p. 289, and his recent ‘Introduction to the Osteology of the 
Mammalia,’ chapter xx. p. 326. 
+ Trans. Linn. Soe. vol. xxv. p. 395. 
t Trans. Linn. Soe. vol. xxvi. p. 620. 
§ ‘Cambridge Journal of Anatomy’ for Noyember 1870, p. 67. 
|| “ Observations on the Limbs of Vertebrate Animals” (1860), communicated 
to the Cambridge Philosophical Society. 
€ Trans. Linn. Soe. vol. xxv. p. 401. 
