(From the Biological Laboratory at Bonn.) 



The Eelation of Muscle Fibrillae to Tendon Fibrillae 

 in voluntary striped Muscles of Vertebrates. 



By 

 W. M. Baldwin 



(Dept. of Anatoray, Cornell University Medical College, New York City.) 



With plate VII. 



The long-contended question over the structural relationship 

 of tendon fibrillae to muscle fibrillae has been brought to our atten- 

 tion by a recent contribution of 0. Schultze. This investigator 

 carried out bis studies on various muscles of Hippocampus, Amphi- 

 oxus, several amphibia, and man, and arrived at the conelusion 

 that these two structural features, muscle fibril and tendon fibril, 

 were directly continuous with each other, perforating the sarco- 

 lemma. Being at the time engaged in a study of certain morpho- 

 logical features of striped-muscle structure, I reviewed my own 

 preparations demonstratiug tbese features with the express purpose 

 of advancing our knowledge in this subject over a larger number 

 of higher vertebrates than this author had used. 



The preparations comprised sections of various muscles, such 

 as intercostales, latissimus dorsi, rectus abdominalis, gastrocnemius, 

 erector Spinae, extrinsic muscles of the eyeball and various muscles 

 of the thigh (together with caudal muscles) of such vertebrates as 

 the tadpole, frog, calf, cat, white mouse, ducken, gray mouse. In 

 addition I utilized specimens of living muscle of the frog and of 

 the tadpole as controls to the fixed and stained preparations. The 

 paraffin method of imbedding was employed in conjunction with 

 Schultze's excellent collodion and Chloroform method of Infiltration. 

 The sections varied in thickness from 2 ,a to 5 ,«. 



The stains used were picric acid, methylene blue, fuchsin S, and 

 eosin, together with combinations of these and various alcoholic 



