333 



almost vertically through the wall to the body cavity where it gives 

 rise to the transversalis abdominis muscle. This muscle 

 remains unaffected by the transverse tendinous inter- 

 sections and dwindles to fascia less than one centi- 

 meter from the mid-ventral line where it again comes in 

 contact with the external fascia. Such a disposition of the fascia is 

 found in only one other instance among the Amphibia viz. : in the 

 Cryptobranchusjaponicus as described by Professor Humphry, 

 (Journ. of Anatomy and Physiology Vol. VI). Thus it will be seen that 

 the dorsal and ventral masses of muscles are separated from each 

 other by the interposed fascia split from the external investment. The 

 dorsal mass is not differentiated into separate muscles, but for the 

 sake of convenience may be considered as composed of two parts : the 

 superior lying above the transverse processes, and the inferior lying 

 beneath these processes. 



The skin having been carefully removed from the body, there will 

 be seen lying along the axis longitudinally disposed rows of cones 

 whose formation and attachments it is impossible to determine before 

 being treated to some staining medium which clearly differentiates 

 the different tissues. I found the following solution to answer this 

 purpose admirably: one part of 1 l i Proz. chromic acid, two 

 parts of 10 Proz. nitric acid, three parts of 5 Proz. ace- 

 tic acid, and two parts of 70 Proz. alcohol. This fluid not 

 only serves to stain but also to macerate the muscular fibre so that 

 it can be detached from the fascia with the greatest ease. Further 

 investigation shows that the transverse septa, which are so constantly 

 present in all other Amphibians , are in Amphiuma transformed 

 into an apparently coarse interlacing net work which 

 forms the lateral boundaries of perfect cones as repre- 

 sented in fig. 1. 



In the superior dorsal mass there are three rows 

 of cones lying side by side. The apices of the row ad- 

 jacent to the axis are directed posteriorly, those of the 

 next row anteriorly, and those of the third row posteriorly. 

 Thus it is seen that the apical direction of the cones varies 

 alternately in the different rows. Eeach cone is introduced 

 into the preceding one about one third of its length as 



/••<? 



Fig. 1. An isolated cone from dorsal muscle of Amphiuma a. fas- 

 cia transversely cut, b. ends of fibres, e. fascia of inner cone 

 d. fibres transversely cut, e. tendon of the cone, /. fascial sheath 

 of cone. 



