264 W. M. Baldwin 



shaped processes of sarcolemma to the apex of which a tendon fibril 

 is attached. 



4th — In the adult those muscles conforming to type 1 still pre- 

 serve the apical processes of their sarcolemma end. 



5th — In the adult these processes of sarcolemma are dove- 

 tailed into the tendon end. 



6th — The sarcolemma at the tendon end of such muscles is 

 not markedly thickened. 



7th — The central tendon of bipenniform muscles (type 2) is in- 

 vested by a connective tissue sheath or peritendinum which consists 

 of connective tissue fibres and cells^ and which separates the tendon 

 fibrillae from the muscle fibres. 



8th — On muscles, conforming to the second type of structure, 

 the sarcolemma end presents a flat surface which rests directly 

 against the attached structure, be it peritendinum, perichondrium, or 

 periosteum. 



9th — This sarcolemma end is considerably thickened and is 

 composed of a homogeneous substance. 



lOth — It presents a number of sarcolemma projections which 

 project into the substance of the muscle fibre. 



llth — These projections are derived from the fused, adjacent 

 walls of the cone-shaped processes of the sarcolemma which were 

 present at an earlier developmental stage of the fibre. 



12th — The muscle fibrillae in adult muscles of this second 

 type preserve their features of cross-striation up to the sarcolemma. 



13th — This sarcolemma end is not perforated either by the 

 tendon fibrillae, the peritendinum fibrillae, or the muscle fibrillae. 



14th — The sarcolemma is not prolonged through the tendon, 

 or over the tendon in either type of muscle. 



15th — ^ The sarcoplasm does not at any place in either type of 

 muscle pass through the sarcolemma. 



Literature. 



Gage, S. H., The Microscope. lOth Edit. The Comstock Publ. Co., Ithaca 



N. Y. 1908. 

 KÖLLiKER, A., Handbuch der Gewebelehre des Menschen. Leipzig 1889. 

 MoTTA-CocA, A. and Ferlito, C, Contributo allo studio dei rapporti tra mus- 



coli e tendini. Monitore zoologico. Vol. X. 1899. 



