208 Relation of Nervous System to the Developing Musculature 



of an almost hyaline suUstance, which stains intensely with Congo red, 

 are found scattered through the musculature in these cases. These 

 conditions are found also in other parts of the specimen where the ner- 

 vous system is still in connection with the musculature. They cannot 

 therefore be considered as due to the lack of nervous stimuli bnt ratlier 

 to imfavorable accidents of the operation. 



Fig. 11. Muscle fibers in cross section, from the same section as Fig. 7; larva sbfown in 

 Pig. 3. /, rtbrillie; np, nucleus of perimysium internum; ns, nucleus of muscle; s, sarco- 

 lemma; v, vacuole; y, yolk spherule. 



Tlie Deuelopinent of tlie Hind Limbs without the Presence of Nerves. 



While the foregoing experiments suffice to show that the grouping of 

 the muscle fibers into individual muscles takes place without the influ- 

 ence of the nervous system, it might be urged that this is the case only 

 in the muscles of comparatively simple arrangement, such as the myo- 

 tomes and their immediate derivatives. It seemed desirable, therefore, 

 to test the power of development of the more complicated musculature of 

 the limbs, when the nerve normally supplying it is prevented from groov- 

 ing into it. At my suggestion ]\Ir. H. L. Langnecker undertook to 

 determine this point. 



The experiment was carried out as follows: A horizontal slit was 

 made just below the notochord in the axis of the body of a young embryo, 

 in the region from which the hind limb would develop. The wound 



