200 



O. P. Dellinger. 



tliut it is fibrillar. It is in reality the eontiimatioii of these myon- 

 eraes into the stalk, and we shonld ex])e('t thein to retain their struc- 

 tnre, as they retain their fnnction in this position. (Fig. 12.) 

 Although no structure has been demonstrated, I do not think we are 

 justified in assuming that it is homogeneous. It is probable that 

 when a method is found to demonstrate it the structure will be found 

 to be fibrillar. 



As mentioned above, the major part of the work on smooth muscle 

 was done by Dr. Duncan in this laboratory, and his results are ready 



13 



12 



Fig. 12. — Myonoiues of Carcesiniu. 



Fig. 13. — Smooth inuscle fiber taken from earthworm. 



(After Duncan.) 



for publication. He used the same stain and, in many cases, the 

 same killing reagents that I have used. His results are in agreement 

 with Avhat I have found in my studies. He finds that the smooth 

 muscle in all the places he examined it (Hydra, sea anemone, star 

 fish clam, Tubifex, Lumbricus, and cat) is distinctly fibrillar. Fig. 

 13, copied from his drawing of the muscle of an earthworm, shows 

 the fibrillar structure in a portion of one of its fibers. The following 

 quotation gives his general conclusions: "All of the structures that 

 we have observed in contractile tissue force upon one the conviction 



