810 REPORT— 1897. 



C. The duration of the activity varied from 45 sees, to 24 hours. Tlie average 

 duration was — 



For the cardiac portion .... lOj Lours. 

 „ middle „ .... 10 j ,, 



„ pyloric „ . . . . 7^ „ 



7. The contractions of the middle and pyloric portions -were, as a rule, more 

 simple and regular than those of the pyloric portion of the stomach. See also 

 Ducceschi (' Ar. It., de Biol.' xxvii. 61), Experiments on dog's stomacli. 



Quite recently (March, 1807), the apparatus being brought into use in a class 

 demonstration, the tracings of one of the pieces of stomach was observed to present 

 an appearance which suggested the idea that the curve was a compound one 

 formed by the superposition of two sets of rhythmical contractions difiering from 

 each oijjer slightly in rate. Diagrams were shown which illustrate two cases of 

 this phenomenon, in one of which there was a difference of 5 and in the other a 

 difference of 17 seconds in the rate of the constituent rhythms. 



Another form ox rhythm occasionally presented by smooth muscles studied in 

 this way is the repetition of a complicated set of contractions, the separate con- 

 tractions of each set differing from each other in appearance, but the set as a 

 whole being a repetition of the previous set. 



It is evident that if two or more such complicated sets of contraction occur 

 simultaneously in the same preparation, the resulting curve will be of a nature to 

 almost defy analysis. 



A few experiments directed to the determination of the influence of hunger 

 and digestion upon the nature of the gastric movements led to no definite result. 



Neither was any connection to be observed between the width of the muscular 

 ring and the complication of the curve. 



2. The Innervation of Motor Tissues, with especial reference to Nerve- 

 endings in the Sensory Muscle-spindles. By Professor G. Carl 

 HuBEB, J/.i>., and Mrs. De Witt. 



The obsei-vations here recorded were made with the methylen-blue method, as 

 modified by Bethe. A 1 per cent, solution of methylen-blue was injected into 

 the blood-vessels ; the tissues to be studied were fixed in ammonium molybdate, 

 sectioned, and double-stained in alum carmine. 



The results obtained were as follows : — 



Nerve-ending in Striated Muscle (rabbit and frog). The neuraxis of the motor 

 neurons terminates, under the sarcolemma, in an end-brush, the fibrils of which 

 present the same structure as the neuraxis itself. The so-called ' sole ' is an accu- 

 mulation of srtreoju^rtswia, at the place of ending of the motor nerve-fibre, which is 

 continuous with the sarcoplasma of the muscle-fibre. The 'sole nuclei' are 

 muscle-nuclei. 



Nerve-ending in Heart-muscle (cat). Heart-muscle receives its innervation 

 from sympathetic nerve-cells. The neuraxes of such nerve-cells terminate in 

 varicose fibrils which end on the heart muscle-cell in small bulbar enlargements 

 or in small clusters of such bulbar enlargements. 



Nerve-ending in Involuntary Smooth Muscles (intestine of cat, frog, and tor- 

 toise). Involuntary smooth muscle receives its nerve-supply from sympathetic 

 nerve-cells. The neuraxes of the sympathetic neurons innervating involuntary 

 muscle end, after repeated branching, in small knobs which rest on the spindle- 

 shaped muscle cells, often near the nucleus. 



Nerve-ending in Muscle-spindle. Muscle-spindles were described by Kblliker 

 ((under the name ' Muskel-Knospen ') in frog's muscle as early as 1862. They 

 were soon after found by Kiihne in the voluntary muscles of other vertebrates. 

 Since that time they have been repeatedly described and variously interpreted. 

 They were described as growth-centres by Kolliker, Bremer, Felix, v. Frauqut^, 



