The Relation of Muscle Fibrillae to Tendon Fibrillae etc. 265 



Eanvier, L., Traite techniqne d'Histologie. 2nd Edit. 1889. 

 ScHiEFFERDECKER, P., Untersuchungen überdieRumpfmuskulaturvonPetromyzon 



fluviatilis, etc. Archiv f. mikrosk. Anat. Bd. LXXYIII. 1911. 

 SCHULTZE, 0., Über den direkten Zusammenhang von Muskelfibrillen und Sehnen- 



fibrillen. Arch. f. mikrosk. Anat. Bd. LXXIX. 1912. 

 Weisman, A., Über die Verbindung der Muskelfasern mit ihren Ansatzpunkten. 



Zeitschr. f. rationelle Medizin. Bd. XII. 1861. 



Explauatioii of figures. 



Plate VII. 



Fig. 1. An isolated muscle fibre with its attached tendon of an extrinsic 

 muscle of the eyeball of a three-weeks-old chicken. The dovetailing 

 of the sarcolemma end with the tendon fibrillae is charaeteristic of 

 muscles belonging to this general type. The muscle fibrillae do not 

 present the features of cross-striation at the muscle end. Magnification 

 1000 diameters. 



Fig. 2. Similar to fig. 1 excepting that the muscle fibril groups are separated 

 from each other by two nuclei. Magnification 1000 diameters. 



Fig. 3. A muscle fibre from an extrinsic eye-muscle of a white mouse twenty- 

 two days old. It presents the same general features as the two pre- 

 ceeding figures. Four tendon fibrillae {A:, are to be noted upon the 

 uppermost aspect of the sarcolemma end. Magnification 1000 diameters. 



Fig. 4. A portion of a muscle fibre and tendon of a thigh muscle of an adult 

 white mouse, which demonstrates the kind of muscle ending com- 

 prised under group 2. The tendon fibrillae (A), are separated from 

 the muscle fibrillae (C), by the peritendinum [B], which contains four 

 cells. Magnification 1000 diameters. 



Fig. 5. Similar to the preceeding. The features of cross-striation can be 

 traced up to the thickened sarcolemma where each is inserted upon 

 a small raised elevation (Bj of the latter. Magnification 1500 diameters. 



Fig. 6. A portion of a muscle fibre of a caudal muscle of a tadpole about 

 5,0 cm long. Each cone-shaped sarcolemma process has attached to 

 it a tendon fibril. Two of the processes derive fibrillae from a large 

 fibroblastic cell situated among the tendon fibrillae. The original 

 preparation from which this sketch was made demonstrates no thickening 

 of the sarcolemma forming these processes. 



Fig. 7. A developing intercostal muscle ofa five-day old white mouse present- 

 ing three cone-shaped sarcolemma processes, each affording attachment 

 to a connective tissue fibril. The fibril on the right is observed to 

 be directly derived from a cell-body. Magnification 1000 diameters. 



Fig. 8. Another developing fibre from the same muscle as the preceeding. In 

 this fibre a more advanced stage of development is seen. Part of 

 the muscle fibre is already attached to the perichondrium of the 

 developing rib-cartilage. Three sarcolemma processes upon the right 

 side of the fibre, however, have not yet reached their definitive attach- 

 ment, but present connective tissue fibrillae affixed to their apex. 

 Magnification 1000 diameters. 



