No. 2.] LIMB-MUSCLES [N AMPHIBIA. BES 
the length of the body these detached ventral myotome-processes 
participate in the formation of continuous lateral bands of 
muscle, which lie one on each side of the body, and which, as 
Maurer has shown, give rise to the abdominal muscles. 
In the tail-region the abdominal muscle-rudiment retains its 
connection with the myotomes (Pl. X, Fig. 12). It tapers 
anteriorly to a very delicate strand of muscle, which becomes 
attached to the posterior edge of the hyoid cartilage just above 
the heart. Further than this I have not followed the ventral 
myotome-processes. A full account of their later development 
has been given by Kaestner and by Maurer. The above 
account covers the period of growth when, if there had been 
any connection between the myotomes and the limbs, it would 
have been evident. 
The anterior limbs of Rana first appear as a thickening of 
the somatopleure just behind the gills. I have been unable to 
trace any connection between the anterior limbs and the myo- 
tomes in Rana. The two structures are so far separated from 
each other, not only as regards their actual position, but also 
as regards the time of their formation, that even if any intimate 
connection does exist between them it is impossible to follow 
it in normal embryos. 
According to Goette’s account, both the anterior and poste- 
rior limbs of Bombinator derive their muscles from the outer 
cells of the segmental plate. Jordan in his account! of the 
development of the anterior extremity of the Anura accepts 
the account already given by Goette, and treats only of the 
later stages of development after the differentiation of tissue 
has already begun. 
The relations between the myotomes and the limbs in the 
frog can be much more easily studied in the posterior than in 
the anterior limb-region. By the time the posterior limb- 
rudiments first begin to make their appearance the ventral 
myotome-processes in the posterior limb-region have just been 
constricted off from the myotomes, and have come to lie imme- 
diately ventral to them (Pl. X, Fig. 18). The rudiments of the 
posterior limbs first appear at the extreme posterior limit of 
1 «“ Die Entwicklung der vorderen Extremitat der Anuren-Batrachier.” 
